Answer:
The correct option is (A)
A. Replace row 4 by its sum with - 4 times row 3.
[tex]\left[\begin{array}{ccccc}1&-4&4&0&-2\\0&2&-6&0&5\\0&0&1&2&-4\\0&0&0&-3&15\end{array}\right][/tex]
w = 8
x = 17/2
y = 6
z = -5
Step-by-step explanation:
The given matrix is
[tex]\left[\begin{array}{ccccc}1&-4&4&0&-2\\0&2&-6&0&5\\0&0&1&2&-4\\0&0&4&5&-1\end{array}\right][/tex]
To solve this matrix we need to create a zero at the 4th row and 3rd column which is 4 at the moment.
Multiply 3rd row by -4 and add it to the 4th row.
Mathematically,
[tex]R_4 = R_4 - 4R_3[/tex]
So the correct option is (A)
A. Replace row 4 by its sum with - 4 times row 3.
So the matrix becomes,
[tex]\left[\begin{array}{ccccc}1&-4&4&0&-2\\0&2&-6&0&5\\0&0&1&2&-4\\0&0&0&-3&15\end{array}\right][/tex]
Now the matrix may be solved by back substitution method.
Bonus:
The solution is given by
Eq. 1
-3z = 15
z = -15/3
z = -5
Eq. 2
y + 2z = -4
y + 2(-5) = -4
y - 10 = -4
y = -4 + 10
y = 6
Eq. 3
2x - 6y + 0z = 5
2x - 6(6) = 5
2x - 12 = 5
2x = 12 + 5
2x = 17
x = 17/2
Eq. 4
w - 4x + 4y + 0z = -2
w - 4(17/2) + 4(6) = -2
w - 34 + 24 = -2
w - 10 = -2
w = -2 + 10
w = 8
Please check my answer! The faculty at a particular school have attended up to an average 4 years of college with a standard deviation of 2 years. Faculty members who are in the lower 10% of the distribution will be offered the opportunity to obtain additional training. A faculty member must have attended less than ___________ years of school to qualify for the training. Round your answer to the year. My answer: 1 – 0.10 = 0.90 0.9 - 0.5 = 0.40 z-score = 1.28 (corresponds with 0.3997) x = (1.28)(2) + 4 = 7 years (rounded)
Answer:
1 year
Step-by-step explanation:
1. Convert 10% into a z-score, using a calculator or whateva
2. Z = -1.281551 ( you can find this by doing the following equation: (x - mean) / (standard deviation)
3. Hence -1.281551 = (x - 4) / 2 or, x = 1.436898, ( rounded to the nearest year ) = 1 year
Arrange the functions for which the result is a non-infinite value and the limit exists in ascending order of their limit values as x tends to infinity. Please see picture attached.
Answer:
see attached
Step-by-step explanation:
The limit as x gets large is the ratio of the highest-degree terms. In most cases, the limit can be found by evaluating that ratio. Where an absolute value is involved, the absolute value of the highest-degree term is used.
If the ratio gives x to a positive power, the limit does not exist. If the ratio gives x to a negative power, the limit is zero.
The arrangement of functions according to the given condition
[tex]m(x)=\frac{4x^{2}-6 }{1-4x^{2} }[/tex]
[tex]h(x)=\frac{x^{3} -x^{2} +4}{1-3x^{2} }[/tex]
[tex]k(x)=\frac{5x+1000}{x^{2} }[/tex]
[tex]i(x)=\frac{x-1}{|1-4x| }[/tex]
[tex]g(x)=\frac{|4x-1|}{x-4}[/tex]
[tex]l(x)=\frac{5x^{2} -4}{x^{2} +1}[/tex]
[tex]f(x)=\frac{x^{2} -1000}{x-5}[/tex]
[tex]j(x)=\frac{x^{2}-1 }{|7x-1|}[/tex]
What is limit?A limit is the value that a function approaches as the input approaches some value.
According to the given question
[tex]l(x)=\frac{5x^{2} -4}{x^{2} +1}[/tex]
⇒[tex]\lim_{nx\to \infty} \frac{5x^{2} -1}{x^{2} +1}[/tex]
⇒[tex]\lim_{x \to \infty} \frac{x^{2} }{x^{2} } \frac{5-\frac{1}{x^{2} } }{1+\frac{1}{x^{2} } }[/tex]
= 5 ([tex]\frac{1}{x^{2} } = 0[/tex] ,as x tends to infinity [tex]\frac{1}{x^{2} }[/tex] tends to 0)
[tex]i(x)=\frac{x-1}{|1-4x|}[/tex]
⇒[tex]\lim_{x \to \infty} \frac{x-1}{|1-4x|}[/tex] = [tex]\lim_{x \to \infty} \frac{x}{x} \frac{1-\frac{1}{x} }{|\frac{-1}{4}+\frac{1}{x} | }[/tex] =[tex]\frac{1}{\frac{1}{4} }[/tex] =[tex]\frac{1}{4}[/tex]
As x tends to infinity 1/x tends to 0, and |[tex]\frac{-1}{4}[/tex]| gives 1/4
[tex]f(x)= \frac{x^{2} -1000}{x--5}[/tex]
⇒[tex]\lim_{x \to \infty} \frac{x^{2} -1000}{x-5}[/tex]= [tex]\lim_{x \to \infty} \frac{x^{2} }{x} \frac{1-\frac{1000}{x^{2} } }{1-\frac{5}{x} }[/tex]= [tex]\lim_{x \to \infty} x\frac{1-\frac{1000}{x^{2} } }{1-\frac{5}{x} }[/tex] ⇒ limit doesn't exist.
[tex]m(x)=\frac{4x^{2}-6 }{1-4x^{2} }[/tex]
⇒[tex]\lim_{x\to \infty} \frac{4x^{2} -6}{1-4x^{2} }[/tex]=[tex]\lim_{x\to \infty} \frac{x^{2} }{x^{2} } \frac{4-\frac{6}{x^{2} } }{\frac{1}{x^{2} } -4}[/tex] [tex]= \lim_{n \to \infty} \frac{4}{-4}[/tex] = -1
As x tends to infinity [tex]\frac{1}{x^{2} }[/tex] tends to 0.
[tex]g(x)=\frac{|4x-1|}{x-4}[/tex]
⇒[tex]\lim_{x\to \infty} \frac{|4x-1|}{x-4}[/tex] = [tex]\lim_{x \to \infty} \frac{|x|}{x} \frac{4-\frac{1}{x} }{1 -\frac{4}{x} } }[/tex] = 4
as x tends to infinity 1/x tends to 0
and |x|=x ⇒[tex]\frac{|x|}{x}=1[/tex]
[tex]h(x)=\frac{x^{3}-x^{2} +4 }{1-3x^{3} }[/tex][tex]\lim_{x \to \infty} \frac{x^{3} -x^{2} +4}{1-3x^{3} }[/tex][tex]= \lim_{x \to \infty} \frac{x^{3} }{x^{3} } \frac{1-\frac{1}{x}+\frac{4}{x^{3} } }{\frac{1}{x^{3} -3} }[/tex] = [tex]\frac{1}{-3}[/tex] =[tex]-\frac{1}{3}[/tex]
[tex]k(x)=\frac{5x+1000}{x^{2} }[/tex]
[tex]\lim_{x \to \infty} \frac{5x+1000}{x^{2} }[/tex] = [tex]\lim_{x \to \infty} \frac{x}{x} \frac{5+\frac{1000}{x} }{x}[/tex] =0
As x tends to infinity 1/x tends to 0
[tex]j(x)= \frac{x^{2}-1 }{|7x-1|}[/tex]
[tex]\lim_{x \to \infty} \frac{x^{2}-1 }{|7x-1|}[/tex] = [tex]\lim_{x \to \infty} \frac{x}{|x|}\frac{x-\frac{1}{x} }{|7-\frac{1}{x}| }[/tex] = [tex]\lim_{x \to \infty} 7x[/tex] = limit doesn't exist.
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How do you determine whether the sign of a trigonometric function (sine, cosine, tangent) is positive or negative when dealing with half angles? Explain your reasoning and cite examples. Why do you think the half-angle identities include positive and negative options but the other identities don't seem to have this option built in?
Answer:
This question is about:
sin(A/2) and cos(A/2)
First, how we know when we need to use the positive or negative signs?
Ok, this part is kinda intuitive:
First, you need to know the negative/positve regions for the sine and cosine function.
Cos(x) is positive between 270 and 90, and negative between 90 and 270.
sin(x) is positive between 0 and 180, and negative between 180 and 360.
Then we need to see at the half-angle and see in which region it lies.
If the half-angle is larger than 360°, then you subtract 360° enough times such that the angle lies in the range between (0° and 360°)
and: Tan(A/2) = Sin(A/2)/Cos(A/2)
So using that you can infer the sign of the Tan(A/2)
Now, why these relationships use the two signs?
Well... this is because of the square root in the construction of the relationships.
This happens because:
(-√x)*(-√x) = (-1)*(-1)*(√x*√x) = (√x*√x)
For any value of x.
so both -√x and √x are possible solutions of these type of equations, but for the periodic nature of the sine and cosine functions, we can only select one of them.
So we should include the two possible signs, and we select the correct one based on the reasoning above.
Please answer this correctly
Answer:
The second question
Step-by-step explanation:
The orca starts at -25 meters. She goes up 25 meters.
up 25 = +25
-25+25=0
Answer:
Option 2
Step-by-step explanation:
The orca swims at the elevation of -25 meters. The orca swims up 25 meters higher than before.
-25 + 25 = 0
I don't know what to do.
Answer:
104.93 in
Step-by-step explanation:
When we draw out a picture of our triangle, we should see that we need to use sin∅ to solve:
sin23° = 41/x
xsin23° = 41
x = 41/sin23°
x = 104.931
Suppose that the scores of bowlers in particular league follow a normal distribution such that the standard deviation of the population is 6. Find the 95% confidence interval of the mean score for all bowlers in this league, using the accompanying data set of 10 random scores. Round your answers to two decimal places and use ascending order. Score 86 86 93 88 98 107 93 75 89
Answer:
A 95% confidence interval for the population mean score for all bowlers in this league is [86.64, 94.48].
Step-by-step explanation:
Since in the question only 9 random scores are given, so I am performing the calculation using 9 random scores.
We are given that the scores of bowlers in particular league follow a normal distribution such that the standard deviation of the population is 6.
The accompanying data set of 9 random scores in ascending order is given as; 75, 86, 86, 88, 89, 93, 93, 98, 107
Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;
P.Q. = [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] ~ N(0,1)
where, [tex]\bar X[/tex] = sample mean score = [tex]\frac{\sum X}{n}[/tex] = [tex]\frac{815}{9}[/tex] = 90.56
[tex]\sigma[/tex] = population standard deviation = 6
n = sample of random scores = 9
[tex]\mu[/tex] = population mean score for all bowlers
Here for constructing a 95% confidence interval we have used a One-sample z-test statistics because we know about population standard deviation.
So, 95% confidence interval for the population mean, [tex]\mu[/tex] is ;
P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5% level
of significance are -1.96 & 1.96}
P(-1.96 < [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < 1.96) = 0.95
P( [tex]-1.96 \times {\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\bar X-\mu}[/tex] < [tex]1.96 \times {\frac{\sigma}{\sqrt{n} } }[/tex] ) = 0.95
P( [tex]\bar X-1.96 \times {\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\mu[/tex] < [tex]\bar X+1.96 \times {\frac{\sigma}{\sqrt{n} } }[/tex] ) = 0.95
95% confidence interval for [tex]\mu[/tex] = [ [tex]\bar X-1.96 \times {\frac{\sigma}{\sqrt{n} } }[/tex] , [tex]\bar X+1.96 \times {\frac{\sigma}{\sqrt{n} } }[/tex] ]
= [ [tex]90.56-1.96 \times {\frac{6}{\sqrt{9} } }[/tex] , [tex]90.56+1.96 \times {\frac{6}{\sqrt{9} } }[/tex] ]
= [86.64 , 94.48]
Therefore, a 95% confidence interval for the population mean score for all bowlers in this league is [86.64, 94.48].
F (X) = x² - 2x and 6(x) = 3x+1
A) Find F(g(-4))
B) Find F(g(x)) simply
C) find g^-1 (x)
Part A
g(x) = 3x+1
g(-4) = 3(-4)+1 ... every x replaced with -4
g(-4) = -12+1
g(-4) = -11
Plug this into the f(x) function
f(x) = x^2 - 2x
f( g(-4) ) = (g(-4))^2 - 2( g(-4) )
f( g(-4) ) = (-11)^2 - 2(-11)
f( g(-4) ) = 121 + 22
f( g(-4) ) = 143 is the answer====================================================
Part B
Plug the g(x) function into the f(x) function
f(x) = x^2 - 2x
f( g(x) ) = ( g(x) )^2 - 2( g(x) ) ... replace every x with g(x)
f( g(x) ) = (3x+1)^2 - 2(3x+1)
f( g(x) ) = (9x^2+6x+1) + (-6x-2)
f( g(x) ) = 9x^2+6x+1-6x-2
f( g(x) ) = 9x^2-1 is the answerNote that we can plug x = -4 into this result and we would get
f( g(x) ) = 9x^2-1
f( g(-4) ) = 9(-4)^2-1
f( g(-4) ) = 9(16)-1
f( g(-4) ) = 144-1
f( g(-4) ) = 143 which was the result from part A
====================================================
Part C
Replace g(x) with y. Then swap x and y. Afterward, solve for y to get the inverse.
[tex]g(x) = 3x+1\\\\y = 3x+1\\\\x = 3y+1\\\\3y+1 = x\\\\3y = x-1\\\\y = \frac{1}{3}(x-1)\\\\y = \frac{1}{3}x-\frac{1}{3}\\\\g^{-1}(x) = \frac{1}{3}x-\frac{1}{3}\\\\[/tex]
PLS HELP ASAP!!!!........
Answer:
aaaaha pues
Step-by-step explanation:
Answer:
what happened
Step-by-step explanation:
Determine if the matrix below is invertible. Use as few calculations as possible. Justify your answer. 3 0 -4 2 0 6 -3 0 8
a. The matrix is invertible. The columns of the given matrix span R^3.
b. The matrix is not invertible. If the given matrix is A, the columns of A do not form a linearly independent set.
c. The matrix is invertible. The given matrix has 2 pivot positions.
d. The matrix is not invertible. If the given matrix is A, the equation Ax = 0 has only the trivial solution.
Answer:
b. The matrix is not invertible. If the given matrix is A, the columns of A do not form a linearly independent set.
Step-by-step explanation:
A square matrix is said to be invertible if the product of the matrix and its inverse result into an identity matrix.
3 0 -4
2 0 6
-3 0 8
Since the second column elements are all zero, the determinant of the matrix is zero ad this implies that the inverse of the matrix does not exist(i.e it is not invertible )
A square matrix is said to be invertible if it has an inverse.
The matrix is not invertible. If the given matrix is A, the columns of A do not form a linearly independent set.
The matrix is given as:
[tex]\left[\begin{array}{ccc}3&0&-4\\2&0&6\\-3&0&8\end{array}\right][/tex]
Calculate the determinant
The determinant of the matrix calculate as:
[tex]|A| = 3 \times(0 \times 8- 6 \times 0) - 0(2 \times 8 - 6 \times -3) -4(2 \times 0 - 0 \times -3)[/tex]
[tex]|A| = 3 \times(0) - 0(34) -4(0)[/tex]
[tex]|A| = 0 - 0 -0[/tex]
[tex]|A| = 0[/tex]
When a matrix has its determinant to be 0, then
It is not invertibleIt does not form a linear independent set.Hence, the correct option is (b)
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Which of the following (x,y) pairs is the solution for the system of equations x+2y=4 and -2x+y=7
Answer:
(-2 ,3)
Step-by-step explanation:
Step 1: Rewrite first equation
x = 4 - 2y
-2x + y = 7
Step 2: Substitution
-2(4 - 2y) + y = 7
Step 3: Solve y
-8 + 4y + y = 7
-8 + 5y = 7
5y = 15
y = 3
Step 3: Plug in y to find x
x + 2(3) = 4
x + 6 = 4
x = -2
forex is the name of the U.S. stock exchange.
-true
-false
Answer:
false
Step-by-step explanation:
hello
this is false
FOREX means Foreign Exchange
it refers to the foreign exchange market
hope this helps
Answer:
true, forex trading is a profitable than staking cryptocurrency. forex trading is the best thing I will refer someone I love because learning never stops and no on is above blowing accounts when beginning Forex
Solve the system of equations for the variables: x+2y-z=3 x+y-2z= -1
Answer:
z=0
x= -5
y=4
Step-by-step explanation:
Check the attachment please
Hope this helps :)
Step-by-step explanation:
x + 2y − z = 3
x + y − 2z = -1
There are three variables but only two equations, so this system of equations is undefined. We cannot solve for the variables, but we can eliminate one of them and reduce this to a single equation.
Double the first equation:
2x + 4y − 2z = 6
Subtract the second equation.
(2x + 4y − 2z) − (x + y − 2z) = (6) − (-1)
2x + 4y − 2z − x − y + 2z = 7
x + 3y = 7
Need help with this as soon as possible.
Answer:
after 9 weeks it would become 9*1+10=19 inches
and after w weeks it will be w*1+10 inches tall
hope this helps
Step-by-step explanation:
Answer:
a) 19 inches
b) 10+w inches
Step-by-step explanation:
The equation for this problem is 10 + w. In the first part, w = 9, so the plant is 19 inches tall.
make d the subject of the formula; n=k/d^2
Answer:
[tex]n = \frac{k}{ {d}^{2} } [/tex]
[tex] {d}^{2} = \frac{k}{n} [/tex]
[tex]d = \sqrt{ \frac{k}{n} } [/tex]
Here is the required firmula....Answer:
d = √(k/n)
Step-by-step explanation:
n = k/d²
n/1 = k/d²
Cross multiply.
k = nd²
Divide both sides by n.
k/n = nd²/n
k/n = d²
Take the square root on both sides.
√(k/n) = √(d²)
√(k/n) = d
please i need this answer right now !!!! Dx
Answer: the answer is d sin30degrees equal 5/x because sin is opposite over hyponuese
What number must you add to complete the square?
X^2 + 8x= 11
A. 12
B. 16
c. 8
D. 4
Answer:
16
Step-by-step explanation:
X^2 + 8x= 11
Take the coefficient of x
8
Divide by 2
8/2 =4
Square it
4^2 = 16
Add 16 to each side
Find the value of c such that the three points (5,5), (-3,1), and (6,c) lie on the same line. Note: Three points are on the same line if the slope of the line through any two points is always the same.
Answer:
c = 5.5
Step-by-step explanation:
We can find the slope of the line using the given points (5,5) and (-3,1) using rise over run:
-4/-8 = 1/2
Now, we can plug in the slope and a point into the equation y = mx + b to find b:
5 = 1/2(5) + b
5 = 2.5 + b
2.5 = b
Then, we can plug in 6 in the point (6,c) to find c:
y = (1/2)(6) + 2.5
y = 3 + 2.5
y = 5.5
c = 5.5
Answer:
c = 5.5
Step-by-step explanation:
Find the slope with two points
m = (y2-y1)/(x2-x1)
m = (1-5)/(-3-5)
= -4/-8
= 1/2
If all the points are on the same line, then they have the same slope
m = (y2-y1)/(x2-x1)
Using the first and third points
1/2 = (c-5)/(6-5)
1/2 = (c-5)/1
1/2 = c-5
Add 5 to each side
5+1/2 = c
5.5 =c
Researchers wanted to know whether it is better to give the diphtheria, tetanus and pertussis (DTaP) vaccine in the thigh or the arm. They collect data on severe reactions to this vaccine in children aged 3 to 6 years old. What would be the best statistical test for them to utilize?
A. One-sample chi-square
B. Linear regression
C. T-test
D. Two-sample chi-square
Answer:
D. Two-sample chi-square
Step-by-step explanation:
A chi-square test is a test used to compare the data that is observed, from the data that is expected.
In a two-sample chi-square test the observed data should be similar to the expected data if the two data samples are from the same distribution.
The hypotheses of the two-sample chi-square test is given as:
H0: The two samples come from a common distribution.
Ha: The two samples do not come from a common distribution
Therefore, in this case, the best statistical test to utilize is the two-sample chi-square test.
Find the product of all positive integer values of $c$ such that $3x^2+7x+c=0$ has two real roots. I will award a lot of points
Answer: 24
Step-by-step explanation:
Let's find one solution:
3x² + 7x + c = 0
a=3 b=7 c=c
First, let's find c so that it has REAL ROOTS.
⇒ Discriminant (b² - 4ac) ≥ 0
7² - 4(3)c ≥ 0
49 - 12c ≥ 0
-12c ≥ -49
[tex]c\leq\dfrac{-49}{-12}\quad \rightarrow c\leq \dfrac{49}{12}[/tex]
Since c must be a positive integer, 1 ≤ c ≤ 4
Example: c = 4
3x² + 7x + 4 = 0
(3x + 4)(x + 1) = 0
x = -4/3, x = -1 Real Roots!
You need to use Quadratic Formula to solve for c = {1, 2, 3}
Valid solutions for c are: {1, 2, 3, 4)
Their product is: 1 x 2 x 3 x 4 = 24
Answer:
$3x^2+7x+c=0$
comparing above equation with ax²+bx+c
a=3
b=7
c=1
using quadratic equation formula
[tex]x = \frac{ - b + - \sqrt{b {}^{2} - 4ac} }{ 2a} [/tex]
x=(-7+-√(7²-4×3×1))/(2×3)
x=(-7+-√13)/6
taking positive
x=(-7+√13)/6=
taking negative
x=(-7-√13)/6=
what is the simplest form of this expression 2(w-1) +(-2)(2w+1)
Answer:
-2w - 4
Step-by-step explanation:
What is the simplest form of this expression
2(w - 1) + (-2)(2w + 1) =
= 2w - 2 - 4w - 2
= -2w - 4
Answer: -2w-4
Step-by-step explanation:
subtract 4w of 2w
2w-2-4w-2
subtract 2 of -2
-2w-2-2
final answer
-2w-4
1. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The expected frequency of satisfied customers from the Berwick sample is________.
a. 60
b. 75
c. 80
d. 90
2. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The expected frequency of satisfied customers from the Milton sample is________.
a. 60
b. 75
c. 80
d. 90
3. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The expected frequency of satisfied customers from the Leesburg sample is________.
a. 60
b. 75
c. 80
d. 90
4. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The chi-square test statistic for these samples is_______.
a. 1.49
b. 2.44
c. 4.15
d. 5.33
5. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The degrees of freedom for the chi-square critical value is_______.
a. 1
b. 2
c. 3
d. 4
6. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
The chi-square critical value using alpha = 0.05 is_______.
a. 2.706
b. 3.841
c. 5.991
d. 7.815
7. Lisa is a regional manager for a restaurant chain that has locations in the towns of Berwick, Milton, and Leesburg. She would like to investigate if a difference exists in the proportion of customers who rate their experience as satisfactory or better between the three locations. The following data represent the number of customers who indicated they were satisfied from random samples taken at each location.
Berwick Milton Leesburg
Number Satisfied 80 85 60
Sample Size 100 120 80
Using alpha = 0.05, the conclusion for this chi-square test would be that because the test statistic is
A. More than the critical value, we can reject the null hypothesis and conclude that there is a difference in proportion of satisfied customers between these three locations.
B. Less than the critical value, we can reject the null hypothesis and conclude that there is a difference in proportion of satisfied customers between these three locations.
C. More than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
D. Less than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
Answer:
1) Option B is correct.
Expected frequency of satisfied customers from the Berwick sample = 75
2) Option D is correct.
Expected frequency of satisfied customers from the Milton sample = 90
3) Option A is correct.
Expected frequency of satisfied customers from the Leesburg sample = 60
4) Option B is correct.
The chi-square test statistic for these samples = 2.44
5) Option B is correct.
The degrees of freedom for the chi-square critical value = 2
6) Option C is correct.
The chi-square critical value using alpha = 0.05 is 5.991
7) Option D is correct.
The conclusion for this chi-square test would be that because the test statistic is less than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
Step-by-step explanation:
Berwick Milton Leesburg
Number Satisfied 80 85 60
Unsatisfied 20 35 20
Sample Size 100 120 80
Since this is a chi test that aims to check if there are differences in the proportion of expected number of customers for each location, we state the null and alternative hypothesis first.
The null hypothesis usually counters the claim we hope to test and would be that there is no difference between the proportion of expected frequency of satisfied customers at the three locations.
The alternative hypothesis confirms the claim we want to test and is that there is a significant difference between the proportion of expected frequency of satisfied customers at the three locations.
So, the total proportion of satisfied customers is used to calculate the expected number of satisfied customers for each of the three locations.
80+85+60= 225
Total number of customers = 100 + 120 + 80 = 300
Proportion of satisfied customers = (225/300) = 0.75
1) Expected frequency of satisfied customers from the Berwick sample = np = 100 × 0.75 = 75
2) Expected frequency of satisfied customers from the Milton sample = np = 120 × 0.75 = 90
3) Expected frequency of satisfied customers from the Leesburg sample = np = 80 × 0.75 = 60
4) Berwick Milton Leesburg
Number Satisfied 80 85 60
Unsatisfied 20 35 20
Sample Size 100 120 80
Proportion for unsatisfied ccustomers = 0.25
So, expected number of unsatisfied customers for the three branches are 25, 30 and 20 respectively.
Chi square test statistic is a sum of the square of deviations from the each expected value divided by the expected value.
χ² = [(X₁ - ε₁)²/ε₁] + [(X₂ - ε₂)²/ε₂] + [(X₃ - ε₃)²/ε₃] + [(X₄ - ε₄)²/ε₄] + [(X₅ - ε₅)²/ε₅] + [(X₆ - ε₆)²/ε₆]
X₁ = 80, ε₁ = 75
X₂ = 85, ε₂ = 90
X₃ = 60, ε₃ = 60
X₄ = 20, ε₄ = 25
X₅ = 35, ε₅ = 30
X₆ = 20, ε₆ = 20
χ² = [(80 - 75)²/75] + [(85 - 90)²/90] + [(60 - 60)²/60] + [(20 - 25)²/25] + [(35 - 30)²/30] + [(20 - 20)²/20]
χ² = 0.3333 + 0.2778 + 0 + 1 + 0.8333 + 0 = 2.4444 = 2.44
5) The degree of freedom for a chi-square test is
(number of rows - 1) × (number of columns - 1)
= (2 - 1) × (3 - 1) = 1 × 2 = 2
6) Using the Chi-square critical value calculator for a degree of freedom of 2 and a significance level of 0.05, the chi-square critical value is 5.991.
7) Interpretation of results.
If the Chi-square test statistic is less than the critical value, we fail to reject the null hypothesis.
If the Chi-square test statistic is unusually large and is greater than the critical value, we reject the null hypothesis.
For this question,
Chi-square test statistic = 2.44
Critical value = 5.991
2.44 < 5.991
test statistic < critical value
The test statistic is Less than the critical value, we fail to reject the null hypothesis and conclude that there is no difference in proportion of satisfied customers between these three locations.
Hope this Helps!!!
Suppose that you have 9 cards. 5 are green and 4 are yellow. The 5 green cards are numbered 1, 2, 3, 4, and 5. The 4 yellow cards are numbered 1, 2, 3, and 4. The cards are well shuffled. Suppose that you randomly draw two cards, one at a time, and without replacement. • G1 = first card is green • G2 = second card is green a) Draw a tree diagram of the situation. (Enter your answers as fractions.) b) Enter the probability as a fraction. P(G1 AND G2) = c)Enter the probability as a fraction. P(at least one green) = d)Enter the probability as a fraction. P(G2 | G1) = _______.
The probability of picking greens on both occasions will be 5/18.
How to explain the probability?The probability of picking greens cards will be:
= 5/9 × 4/8
= 5/18
The probability of picking at least one green will be:
= 1 - P(both aren't green)
= 1 - (4/9 × 3/8)
= 1 - 1/6.
= 5/6
From the tree diagram, the probability as a fraction of P(G2 | G1) will be:
= 4/8 = 1/2
Learn more about probability on:
brainly.com/question/24756209
#SPJ1
Evaluate. Write your answer as a fraction or whole number without exponents. 1/10^-3 =
Answer:
1000
Step-by-step explanation:
=> [tex]\frac{1}{10^{-3}}[/tex]
According to the law of exponents, [tex]\frac{1}{a^{-m}} = a^{m}[/tex]
So, it becomes
=> [tex]10^{3}[/tex]
=> 1000
Which point is located at (Negative 3.5, Negative 4.5)? On a coordinate plane, point A is 3.5 units to the left and 4.5 units down. Point K is 3.5 units to the right and 4.5 units up. Point R is 3.5 units to the left and 4.5 units up. Point Y is 4.5 units to the left and 3.5 units down. point A point K point R point Y
Answer:
Point A
Step-by-step explanation:
We know that on a coordinate plane, negative numbers can be found by moving down or moving to the left. This point must be found by moving down and left. To establish whether it is point A or point Y, we can remember that x coordinates move left and right and y coordinates move up and down. So, we would need to move 3.5 units left for x and then 4.5 units down for y. This leads us to point A.
hope this helps!
Answer:
it is point A
Step-by-step explanation:
are the two triangles below similar
Answer:
Hey!
Your answer is YES!
AKA the Last Option on your screen!
Step-by-step explanation:
It is this because...
They both have the angles 105 in it...
And looking at the other angle on the smaller one (25)
50 + 25 = 75 ... 180 - 75 = 105
WE HAVE 105 as an angle on the larger triangle...which makes them SIMILAR but congruent Angles!
It cant be the "corresponding sides" as we do not have the notations (lines intersecting the sides) that let us know that the lines are the same.
Hope this helps!
(0, 3) and (-2, -1)
Write an equation in slope intercept from of the line that passes through the given points.
Answer:
y = 2x + 3
Step-by-step explanation:
Slope Formula: [tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Slope-Intercept Form: y = mx + b
Step 1: Find slope m
m = (-1 - 3)/(-2 - 0)
m = -4/-2
m = 2
y = 2x + b
Step 2: Rewrite equation
y = 2x + 3
*You are given y-intercept (0, 3), so simply add it to your equation.
The total area under the standard normal curve to the left of zequalsnegative 1 or to the right of zequals1 is
Answer:
0.3174
Step-by-step explanation:
Z-score:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the area under the normal curve to the left of Z. Subtracting 1 by the pvalue, we find the area under the normal curve to the right of Z.
Left of z = -1
z = -1 has a pvalue of 0.1587
So the area under the standard normal curve to the left of z = -1 is 0.1587
Right of z = 1
z = 1 has a pvalue of 0.8413
1 - 0.8413 = 0.1587
So the area under the standard normal curve to the right of z = 1 is 0.1587
Left of z = -1 or right of z = 1
0.1587 + 0.1587 = 0.3174
The area is 0.3174
If the 2412 leaves are not a random sample, but the researchers treated the 2412 leaves as a random sample, this most likely made the data more:_____________.1. accurate, but not precise2. precise, but not accurate3. neither4. both accurate and precise
Answer:
2. Precise but not accurate
Step-by-step explanation:
In a high precision, low accuracy case study, the measurements are all close to each other (high agreement between the measurements) but not near/or close to the center of the distribution (how close a measurement is to the correct value for that measurement)
A lady buys bananas at 3 Rs 5 and sells them at 2 Rs for Rs 5; find her gain percent.
Answer:
50%
Step-by-step explanation:
Cost of 3 bananas= Rs. 5 ⇒ cost of 1 banana= Rs. 5/3
Selling price of 2 bananas= Rs. 5 ⇒ selling price of 1 banana= Rs. 5/2
Gain= Rs. (5/2- 5/3)= Rs. (15/6- 10/6)= Rs. 5/6
Gain %= 5/6÷5/3 × 100%= 50%
If f(x)=2x−1, show that f(f(x))=4x−3. Find f(f(f(x))).
Answer: f(f(f(x)))=8x-7
Step-by-step explanation:
Since we were given f(x) and f(f(x)), We plug that into f(x) again to get f(f(f(x))).
2(4x-3)-1 [distribute]
8x-6-1 [combine like terms]
8x-7