Answer:
a) 95% confidence intervals are
(64.188, 72.652)
b) Mike use
(t₀.₀₂₅ , ₆)= 2.4469
Step-by-step explanation:
Step(i):-
Given data
x : 65 71 74 61 66 70 72
Mean of 'x'
x⁻ = ∑ x / n
[tex]x^{-} = \frac{65+71+74+61+66+70+72}{7} = 68.42[/tex]
x : 65 71 74 61 66 70 72
x - x⁻ : -3.42 2.58 5.58 -7.42 -2.42 1.58 3.58
(x-x⁻)² : 11.69 6.65 31.13 55.05 5.85 2.49 12.81
∑((x-x⁻)²) = 125.67
Variance
S² = ∑((x-x⁻)²) / n-1 = [tex]\frac{125.67}{6} = 20.945[/tex]
Standard deviation S = √20.945 =4.576
Step(ii):-
95% confidence intervals are determined by
[tex](x^{-} - t_{\alpha } \frac{S}{\sqrt{n} } , x^{-} +t_{\alpha } \frac{S}{\sqrt{n} })[/tex]
Degrees of freedom
ν =n-1 = 7-1 =6
[tex]t_{\frac{\alpha }{2} , n-1 } = t_{(\frac{0.05}{2} , 6)}[/tex] = (t₀.₀₂₅ , ₆)= 2.4469
[tex](68.42 - 2.4469 \frac{4.576}{\sqrt{7} } , 68.42 +2.4469\frac{4.576}{\sqrt{7} })[/tex]
( 68.42 - 4.232, 68.42 + 4.232)
(64.188, 72.652)
Conclusion:-
95% confidence intervals are
(64.188, 72.652)
Answer:
64.19 to 72.67
Step-by-step explanation:
If a person invests $290 at 6% annual interest, find the approximate value of the investment at the end of 15 years.
Answer:
$261
Step-by-step explanation:
Simple equation to remember.
I = PRT
In this case, "I" means investment, "P" means principal, a fancy term for saying the starting money, "R" means rate in decimal form (just move the decimal two places to the left to convert the percent to decimal), and "T" means time, which is usually in years.
All you do is just plug in 290 as P, 0.06 as R, and 15 as the T, and then you multiply that all together to get.
However, this is only the simple investment equation, there are other equations such as the compound equation used for interest. I'm assuming you're only using the normal interest equation.
What is LCM? And what is the formula for that?
Answer:
LCM stands for Least Common Multiple
To calculate LCM you need to divide the no.s given by smallest divisor going to the greatest until the no.s can be divided no more
The Marine Corps is ordering hats for all the new recruits for the entire next year. Since they do not know the exact hat sizes they will use statistics to calculate the necessary numbers. This is the data from a sample of the previous recruits: 7.2, 6.8, 6, 6.9, 7.8, 6.2, 6.4, 7.2, 7.4, 6.8, 6.7, 6, 6.4, 7, 7, 7.6, 7.6, 6, 6.8, 6.4 a. Display the data in a line plot and stem-and-leaf plot. (These plots don’t need to be pretty; just make sure I can make sense of your plots.) Describe what the plots tell you about the data. b. Find the mean, median, mode, and range. c. Is it appropriate to use a normal distribution to model this data? d. Suppose that the Marine Corps does know that the heights of new recruits are approximately normally distributed with a mean of 70.5 inches and a standard deviation of 1.5 inches. Use the mean and standard deviation to fit the new recruit heights to a normal distribution and estimate the following percentages. d1. What percent of new recruits would be taller than 72 inches? d2. What percent of new recruits would be shorter than 67.5 inches? d3. What percent of new recruits would be between 69 and 72 inches? d4. Between what two heights would capture 95% of new recruits?? By using statistics are the numbers changed to whole numbers?
Answer:
60-|||
61-
62-||
62
64-|||
65
66
67-|
68-|||
69-|
70-||
71
72-||
73
74-||
75
76-||
77
78-|
This is a stem and leaf plot.
mean is 138.2/20=6.91
median of 20 is half way between 10th and 11th or an ordered plot. The 10th and the 11th are both 6.8, so that is the median.
6.4 and 6.8 are modes, but they are so minimal I would say there isn't a clear mode.
The range is 1.8, the largest-the smallest
This is not a normal distribution.
z=(x-mean) sd
a.(72-70.5)/1.5=1 so z>1 is the probability or 0.1587.
b.shorter than 67.5 inches is (67.5-70.5)/1.5 or z < = -2, and probability is 0.0228.
c.Between 69 and 72 inches is +/- 1 sd or 0.6826.
95% is 1.96 sd s on either side or +/- 1.96*1.5=+/- 2.94 interval on either side of 70.5
(67.56, 73.44)units in inches
Step-by-step explanation:
hey guys please help me
Answer:
5/6
Step-by-step explanation:
The probability of the 10th roll will be 6 is 1 out 6 because there's only one side with 6 (we spouse the dice is not biased) so the probability of the roll not to be 6 is 5/6
The scores for all the sixth graders at Roberts School on a statewide test are normally distributed
with a mean of 76 and a standard deviation of 10.
1. What percent of the scores were below 66
Answer:
15.87%
Step-by-step explanation:
z-score referred to standard score and it provide idea of the difference from the mean a data point it gives measurement of all standard deviations that falls below as well as above the mean in a given score
we were given:
mean of 76
deviation of 10
To calculate the z- scores
z-score = (the given score of interest - mean score given)/ standard deviation.
Z- score =66 - 76)/10
= -10/10 = -1.
Hence our z- score= -1
The next step is to look up the z-score of -1 on a z-table z-table
if you look for A z-score of -1 on the z- score table you will see that a z- score of (-1) has 15.87% of all scores below it.
Therefore, the percent of the scores that were below 66 is 15.87%
BELOW IS THE ATTACHMENT OF THE Z-SCORE TABLE
2(x + 14) = 42 can someone please help me with a step by step explanation
Answer:
Nah bro I gotchu! 2x+28=42
2x=42-28
2x=14
x=7
:)
Step-by-step explanation:
In a marketplace, a box of peaches can be purchased for $78.95 per box. One box contains 50 peaches. How much would you have to pay to buy 9 peaches?
(Hint: Convert 9 peaches into dollars.)
Round your answer to the nearest hundredth. Do not type the units ($) in the space below.
Answer:
The cost of 9 peaches will be 9/50 th of the price of 50 peaches. Therefore, the answer is 9/50 * 78.95 ≈ $14.21.
Answer:
14.21
Step-by-step explanation:
To find the cost of 9 peaches, you would need to find the cost of one peach. To do this, you would need to divide 78.95 by 50. This comes out to 1.579 per peach. To find the cost of nine peaches, you would multiply this number by 9 to get 14.211. We are not done yet since you have to round to the nearest hundredth. When rounded, you get 14.21.
Hence,
the cost of nine peaches is 14.21 dollars.
Hope this helps!!! PLZ MARK BRAINLIEST!!!
The slope of the line passing through the points (7, 5) and (21, 15) is
Answer:
5/7
Step-by-step explanation:
We are given two points so we can find the slope by using
m = (y2-y1)/(x2-x1)
= (15-5)/(21-7)
=10/14
5/7
The point (3, 6) is on the graph of y= 5f(2(x+3))-4 . Find the original point on the graph of y=f(x).
Answer:
(12, 2) is the original point on the graph of [tex]y=f(x)[/tex].
Step-by-step explanation:
Given:
[tex]y= 5f(2(x+3))-4[/tex] has a point (3, 6) on its graph.
To find:
Original point on graph [tex]y=f(x)[/tex] = ?.
Solution:
We are given that The point (3, 6) is on the graph of [tex]y= 5f(2(x+3))-4[/tex]
If we put x = 3 and y = 6 in [tex]y= 5f(2(x+3))-4[/tex], it will satisfy the equation.
Let us the put the values and observe:
[tex]6= 5f(2(3+3))-4\\\Rightarrow 6= 5f(2(6))-4\\\Rightarrow 6= 5f(12)-4\\\Rightarrow 6+4=5f(12)\\\Rightarrow 5f(12)= 6+4\\\Rightarrow 5f(12)= 10\\\Rightarrow f(12)= \dfrac{10}{5}\\\Rightarrow f(12)= 2\\OR\\\Rightarrow 2=f(12)[/tex]
Now, let us compare the above with the following:
[tex]y=f(x)[/tex]
we get y = 2 and x = 12
So, the original point on graph of [tex]y=f(x)[/tex] is (12, 2).
solve the right triangle abc for the missing side and angles to the nearest tenth given sides a=13.2 and b=17.7
Step-by-step explanation:
Assuming c is the hypotenuse:
c = √(a² + b²)
c = 22.1
tan A = a/b
A = 36.7°
tan B = b/a
B = 53.3°
Which measurements could create more than one triangle?
2 of 4 QUESTION
A triangle with sides measuring 10 cm and 20 cm and an included angle
measuring 65°
A triangle with sides measuring 15 inches, 20 inches, and 25 inches
O A triangle with sides measuring 20 cm, 9 cm, and 10 cm
O A right triangle with acute angles measuring 45° and 45°
Answer: A right triangle with acute angles measuring 45° and 45°
Step-by-step explanation:
This question is related to the criteria of congruence for triangles.
The criteria are:
SSS (you know the 3 sides)
SAS (you know two sides, and the angle between those two sides)
ASA (you know two angles, and the side between those two angles)
AAS (you know two angles, and one side).
So for the given examples, the only one that does not reach any of those criteria is the last option, where we only have the angles:
45°, 45° and 90°.
This means that we can craft multiple triangles with this data:
this is a triangle rectangle where the length of the cathetus is the same, that is the only restriction.
For example we can have lengths:
1, 1 and √2
or 2, 2 and √(2^2 + 2^2) = √8
Answer:
A right triangle with acute angles measuring 45° and 45°
Step-by-step explanation:
What is the length of AC ?
Answer:
D. 24
Step-by-step explanation:
AM: 12 (radius)
AC: 24 (diameter)
How many solutions does the system have? { y = − 3 x + 9 3 y = − 9 x + 9 ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ y=−3x+9 3y=−9x+9
Answer:
no solutions
Step-by-step explanation:
y = − 3 x + 9
3 y = − 9 x + 9
Multiply the first equation by -3
-3(y )=-3( − 3 x + 9)
-3y = 9x -27
3 y = − 9 x + 9
-------------------------
0 = 0 -18
0 = -18
This is never true so there are no solutions
Answer:
for kahn academy -- b -- ( no solutions)
Step-by-step explanation:
what is the solution of x^y=y^x and y=2x?
Answer:
x=0, y=0
x=2, y=4
Step-by-step explanation:
x^y= y^xy= 2xx^(2x)= (2x)^x(x^2)^x= (2x)^xx^2=2xx(x-2)=0x=0 ⇒ y=0x=2 ⇒ y=4Answer:
x = 2, y = 4.
Step-by-step explanation:
x^y = y^x
Substitute y = 2x in the above:
x^2x = (2x)^x
x^2x = 2*x * x^x Divide both sides by x^x:
x^2x / x^x = 2*x
x^(2x-x) = 2^x
x^x = 2^x
So x = 2.
and y = 2x = 4.
We can also make x = 0 and y = 0 but
I'm not sure if this result is valid because 0^0 is undefined.
Looking further into this there seems to be different opinions on this with some mathematicians say 0^0 = 1, so x=0, y = 0 may be acceptable.
Anybody get this? Thanks in advanced
Answer:
x = 6 and y = 2
Step-by-step explanation:
2x + 3y = 18 .......... Eqn 1
3x - 3y = 12 ........... Eqn 2
Add both Equations to eliminate y
we have
2x + 3x + 3y - 3y = 18 + 12
5x = 30
Divide both sides by 5
5x / 5 = 30/5
x = 6
Substitute x = 6 into any of the Equations
Using equation 1
we have
2(6) + 3y = 18
3y = 18 - 12
3y = 6
Divide both sides by 3
That's
3y/3 = 6/3
y = 2
Therefore x = 6 and y = 2
Hope this helps
-73 + 28
Can anybody help me with this
Answer:
-45 is the answer
Step-by-step explanation:
PLZZ MARK BRAINLIEST
A rectangular prism made of wood has a length of 10 centimeters, a width of 8 centimeters, and a height of 12 centimeters. A rectangular hole
with a length of 2 centimeters and a width of 3 centimeters is cut through the prism as shown. What is the volume of the resulting figure?
3 cm
2 cm
12 cm
8 cm
10 cm
Answer: its B 888 cm
Step-by-step explanation: hope this helps let me know if wrong ill fix it
what is the difference of rational expressions below 6x/x-3 - 5/x
Answer:
[tex]$ \frac{6x^2-5x+15 }{x^2-3x} $[/tex]
Step-by-step explanation:
[tex]$\frac{6x}{x-3} -\frac{5}{x} $[/tex]
[tex]$\frac{6x(x)}{x(x-3)} -\frac{5(x-3)}{x(x-3)} $[/tex]
[tex]$\frac{6x^2}{x^2-3x} -\frac{5x-15}{x^2-3x} $[/tex]
[tex]$ \frac{6x^2-5x+15 }{x^2-3x} $[/tex]
When five times a number is decreased by 8, the result is 7. What is the number?
The number is
Answer:
3
Step-by-step explanation:
5x - 8 = 7
5x = 7+8
5x = 15
x = 15 ÷ 5
x = 3
Find equations for the tangent lines and the normal lines to the hyperbola for the given value of x. (The normal line at a point is perpendicular to the tangent line at the point.)
Answer:
P (7, 28)
Step-by-step explanation:
2. A line passes through the point (0,4).
The gradient of this line is 2.
Write down the equation of this line
Answer:
[tex]\boxed{y = 2x+4}[/tex]
Step-by-step explanation:
Gradient = m = 2
Y-intercept = b = 4 (Because here x = 0 as in the point (0,4))
So, the equation becomes
=> [tex]y = mx+b[/tex]
=> [tex]y = 2x+4[/tex]
Carlos mixed 3 1⁄2 cups of red paint with 4 1⁄2 cups of yellow paint to make an orange paint. How many cups of red paint and how many cups of yellow paint will Carlos need to make 12 cups of the same shade of orange paint? Solve in at least three different ways.
Answer:
The answer is " red cups is "5.25""
Step-by-step explanation:
Given:
red paint= [tex]3\frac{1}{2}= \frac{7}{2} =3.5[/tex]
yellow paint= [tex]4\frac{1}{2}= \frac{9}{2} =4.5[/tex]
total cups=12
i) The Ratio of red and yellow is= 3.5 : 4.5
If the red cups are= [tex]\frac{3.5}{8}[/tex]
number of red cups:
[tex]\to \frac{3.5}{8}\times 12\\\\\to \frac{3.5}{2}\times 3\\\\\to 3.5\times 1.5\\\\\to 5.25[/tex]
ii)
[tex]\to 3.5x+4.5x=12......(a)\\\\\to 8x=12\\\to x=\frac{12}{8}\\\\\to x=\frac{3}{2}\\\\[/tex]
put the value of x in equation (a):
[tex]\to 3.5 \times \frac{3}{2}+4.5\times \frac{3}{2}=12\\\\\to 35 \times \frac{3}{20}+45\times \frac{3}{20}=12\\\\\to 5.25+6.75=12[/tex]
iii)
if [tex]\frac{4.5}{8} \times 12= 6.75[/tex] yellow cups used in making orange paint
so, red paint +yellow paint = total cups
let, red paint cups =x
⇒x+6.75=12
⇒x=12-6.75
⇒x=5.25
The value of red cups is 5.25.
US consumers are increasingly using debit cards as a substitute for cash and checks. From a sample of 100 consumers, the average amount annually spent on debit cards is $7,790. Assume that this average was based on a sample of 100 consumers and that the population standard deviation is $500.
A. At 99% confidence, what is the margin of error?
B. Construct the 99% confidence interval for the population mean amount spent annually on a debit card.
Answer:
A. Margin of error = 128.79
B. The 99% confidence interval for the population mean is (7661.21, 7918.79).
Step-by-step explanation:
We have to calculate a 99% confidence interval for the mean.
The population standard deviation is know and is σ=500.
The sample mean is M=7790.
The sample size is N=100.
As σ is known, the standard error of the mean (σM) is calculated as:
[tex]\sigma_M=\dfrac{\sigma}{\sqrt{N}}=\dfrac{500}{\sqrt{100}}=\dfrac{500}{10}=50[/tex]
The z-value for a 99% confidence interval is z=2.576.
The margin of error (MOE) can be calculated as:
[tex]MOE=z\cdot \sigma_M=2.576 \cdot 50=128.79[/tex]
Then, the lower and upper bounds of the confidence interval are:
[tex]LL=M-t \cdot s_M = 7790-128.79=7661.21\\\\UL=M+t \cdot s_M = 7790+128.79=7918.79[/tex]
The 99% confidence interval for the population mean is (7661.21, 7918.79).
A line through the points (2, -9) and (j, 17) is parallel to the line 2x + 3y = 21. What is the value of j?
Answer:
j = -37
Step-by-step explanation:
First find the slope of 2x + 3y = 21
Solve for y
Subtract 2x from each side
2x-2x + 3y =-2x+ 21
3y = -2x+21
Divide by 3
3y/3 = -2x /3 + 21/3
y = -2/3 x +7
This is in slope intercept form y = mx+b where m is the slope and b is the y intercept
m = -2/3
The slope of parallel lines are equal
Using the two points
m = (y2-y1)/(x2-x1)
-2/3 = (17 - -9)/(j-2)
-2/3 = (17 +9)/(j-2)
Using cross products
-2(j-2) = 3 ( 17+9)
-2j +4 = 26*3
-2j +4 = 78
Subtract 4 each side
-2j = 78-4
-2j = 74
Divide by -2
-2j/-2 = 74/-2
j = -37
What is the value of 45-0.023
The value is 44.977
Feel pleasure to help u
Answer:
44.977
Step-by-step explanation:
What is the x-intercept of the graph?
Answer: (6,0)
Step-by-step explanation: To find the x-intercept, we plug a 0 in for y.
So we have 2x - 3(0) = 12.
Simplifying from here, we have 2x = 12.
Now divide both sides by 2 and we get x = 6.
So our x-intercept is 6.
This means that our line crosses the x-axis 6
units to the right of the origin or at the point (6,0).
Answer:
(6,0)
Step-by-step explanation:
The x intercept is where the graph crosses the x axis
A bag contains 75 marbles:35 are blue and 25 of these blue marbles are swirled. The rest of them are red, and 30 of the red ones are swirled. The marbles that are not swirled are clear. What is the probability of drawing? (a) A blue marble (b) A blue swirled marble (c) A red clear marble.
Answer:
a) 35/75
b)25/75
c)10/75
Step-by-step explanation:
The amount of time spent updating websites for small businesses averages 50 minutes per week with a standard deviation of 10 minutes per week. if we consider the distribution of times as mound-shaped and symmetric, use the standard deviation to explain where we would expect "most" of the times will fall each week?
a) Way too long
b) Between 30 and 70 minutes
c) Between 40 and 60 minutes
d) Between 20 and 80 minutes
Answer:
I think the answer is C - Between 40 and 60 minutes
Step-by-step explanation:
Since each week the amount of time spend updating websites takes 50 minutes per week with an addition of 10 minutes it would be 1 hour per week (60 minutes)
A research group wants to know if the online platform to play Settlers of Catan is being accessed more after the stay at home order than before it. The mean for number of games started per minute before the stay at home order was 1000. The researchers hypothesize that after the stay at home order, the online platform was accessed more so than before the stay at home order. They set alpha = .05 The mean for number of games started per minute after the stay at home order, was 1378 with a standard deviation of 489. The sample size was 108,000.
a. Given this conclusion, what can you say about the p value of this test statistic?
b. Please calculate the effect size. Is it small, medium, or large?
Answer:
a) The P-value is 0.
At a significance level of 0.05, there is enough evidence to support the claim that the online platform was accessed significantly more so than before the stay at home order.
b) Effect size d = 0.77
Medium.
Step-by-step explanation:
This is a hypothesis test for the population mean.
The claim is that the online platform was accessed significantly more so than before the stay at home order.
Then, the null and alternative hypothesis are:
[tex]H_0: \mu=1000\\\\H_a:\mu> 1000[/tex]
The significance level is 0.05.
The sample has a size n=108000.
The sample mean is M=1378.
As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=489.
The estimated standard error of the mean is computed using the formula:
s_M=\dfrac{s}{\sqrt{n}}=\dfrac{489}{\sqrt{108000}}=1.488
Then, we can calculate the t-statistic as:
t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{1378-1000}{1.488}=\dfrac{378}{1.488}=254.036
The degrees of freedom for this sample size are:
[tex]df=n-1=108000-1=107999[/tex]
This test is a right-tailed test, with 107999 degrees of freedom and t=254.036, so the P-value for this test is calculated as (using a t-table):
[tex]\text{P-value}=P(t>254.036)=0[/tex]
As the P-value (0) is smaller than the significance level (0.05), the effect is significant.
The null hypothesis is rejected.
At a significance level of 0.05, there is enough evidence to support the claim that the online platform was accessed significantly more so than before the stay at home order.
The effect size can be estimated with the Cohen's d.
This can be calculated as:
[tex]d=\dfrac{M-\mu}{\sigma}=\dfrac{1378-1000}{489}=\dfrac{378}{489}=0.77[/tex]
The values of Cohen's d between 0.2 and 0.8 are considered "Medium", so in this case, the effect size d=0.77 is medium.
Want Brainliest? Get this correct Which of the following is the quotient of the rational expressions shown below? Make sure your answer is in reduced form.
Answer:
B.
Step-by-step explanation:
First, notice that we can cancel out an x in the second term. Thus:
[tex]\displaystyle \frac{3x^2}{x^2+x} =\frac{3x^2}{x(x+1)} =\frac{3x}{x+1}[/tex]
As with the last question, change the sign to multiplication and "flip" the second term:
[tex]\displaystyle \frac{2x-1}{x+1}\cdot \frac{x+1}{3x}[/tex]
Multiply straight across:
[tex]\displaystyle =\frac{(2x-1)(x+1)}{(x+1)(3x)}[/tex]
We can cancel the (x + 1) term:
[tex]\displaystyle =\frac{2x-1}{3x}[/tex]
This cannot be simplified further. Hence, our answer is B.
Answer:
It is B)
Step-by-step explanation:
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