Answer:
55.11% probability that the mean life a random sample of 9 such blenders falls between 4.5 and 5.1 years.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal probability distribution
When the distribution is normal, we use the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
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 probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this question:
[tex]\mu = 5, \sigma = 1, n = 9, s = \frac{1}{\sqrt{9}} = 0.3333[/tex]
Find the probability that the mean life a random sample of 9 such blenders falls between 4.5 and 5.1 years.
This is the pvalue of Z when X = 5.1 subtracted by the pvalue of Z when X = 4.5. So
X = 5.1
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{5.1 - 5}{0.3333}[/tex]
[tex]Z = 0.3[/tex]
[tex]Z = 0.3[/tex] has a pvalue of 0.6179
X = 4.5
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{4.5 - 5}{0.3333}[/tex]
[tex]Z = -1.5[/tex]
[tex]Z = -1.5[/tex] has a pvalue of 0.0668
0.6179 - 0.0668 = 0.5511
55.11% probability that the mean life a random sample of 9 such blenders falls between 4.5 and 5.1 years.
Karl has $1,500. He spends $375 on a phone and of the rest on a gaming system. What percent of his money is spent on the gaming system?
Answer:
75 %
Step-by-step explanation:
1500 - 375 =1125
So 1125 is spent on the gaming system
Take this over the total amount to get the decimal form
1125/1500 =.75
Change to percent form
75 %
Answer:
75%
Step-by-step explanation:
First we have to find the amount he is using for the gaming system which is
$1500 - $375 = $1125
Now we will express $1125 as a percentage of the total amount and we do that like this;
[tex]\frac{1125}{1500}[/tex] * 100%
= [tex]\frac{1125}{15}[/tex]
=75%
Evaluate the expression (image provided). A.) 1.5 B.) 6 C.) 6^15 D.) 1.5^6
Answer:
1.5
Step-by-step explanation:
6 to the log base of 6 will be one (they essentially cancel each other out, log is the opposite of exponents) and we are left with 1.5.
Find the z-score corresponding to the given area. Remember, z is distributed as the standard normal distribution with mean of and standard deviation .
Answer:
Step-by-step explanation:
The z-score corresponding to a given area of a distribution, is the number of standard deviations that the values in that area have/are from the mean.
In this case, we have a STANDARD normal distribution. In a standard normal distribution, the mean is 0 and the standard deviation is 1.
The Z-score corresponding to a given area, say the 30th percentile is
X = 0 + (-0.524)(1)
Hence, the X (number of values in the given percentile - in this case, 30th) is same as the z-table or z-calculator value for the 30th percentile in ANY normal distribution.
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
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
Please help. !!!!! Only if you are good at college algebra
What is a15 of the sequence −7,2,11,…
?
Step-by-step explanation:
a=-7
d=9
n=15
we have to find a15
a(n)= a+(n-1)d
a(15)= -7+(15-1)9
a(15)= -7+126
a(15)=119
so 15 term of the sequence is 119
The 15th term in the given sequence is 119.
The given sequence is −7,2,11,…
Here, a=-7, d=9
What is the formula to find the nth term of the sequence?The formula to find the nth term of the sequence is [tex]a_{n} =a+(n-1)d[/tex].
Now, [tex]a_{15} =-7+(15-1) \times9=119[/tex].
Therefore, the 15th term in the sequence is 119.
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For a certain salesman, the probability of selling a car today is 0.30. Find the odds in favor of him selling a car today.
Answer:
The odds in favor of him selling a car today are 3 to 10
Step-by-step explanation:
Probability and odds:
Suppose we have a probability p.
The odds are of: 10p to 10
In this question:
Probability of selling a car is 0.3.
10*0.3 = 3
So the odds in favor of him selling a car today are 3 to 10
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:
16 square meters is equivalent to how many square yards?
Answer:
16 square meters is equivalent to 19.14 square yards
Hope this helps you
The mean MCAT score 29.5. Suppose that the Kaplan tutoring company obtains a sample of 40 students with a mean MCAT score of 32.2 with a standard deviation of 4.2. Test the claim that the students that took the Kaplan tutoring have a mean score greater than 29.5 at a 0.05 level of significance.
Answer:
We conclude that the students that took the Kaplan tutoring have a mean score greater than 29.5.
Step-by-step explanation:
We are given that the Kaplan tutoring company obtains a sample of 40 students with a mean MCAT score of 32.2 with a standard deviation of 4.2.
Let [tex]\mu[/tex] = population mean score
So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \leq[/tex] 29.5 {means that the students that took the Kaplan tutoring have a mean score less than or equal to 29.5}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] > 29.5 {means that the students that took the Kaplan tutoring have a mean score greater than 29.5}
The test statistics that will be used here is One-sample t-test statistics because we don't know about population standard deviation;
T.S. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] ~ [tex]t_n_-_1[/tex]
where, [tex]\bar X[/tex] = sample mean MCAT score = 32.2
s = sample standard deviation = 4.2
n = sample of students = 40
So, the test statistics = [tex]\frac{32.2-29.5}{\frac{4.2}{\sqrt{40} } }[/tex] ~ [tex]t_3_9[/tex]
= 4.066
The value of t-test statistics is 4.066.
Now, at 0.05 level of significance, the t table gives a critical value of 1.685 at 39 degrees of freedom for the right-tailed test.
Since the value of our test statistics is more than the critical value of t as 4.066 > 1.685, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region.
Therefore, we conclude that the students that took the Kaplan tutoring have a mean score greater than 29.5.
Heather is writing a quadratic function that represents a parabola that touches but does not cross the x-axis at x = –6. Which function could Heather be writing? f(x) = x2 + 36x + 12 f(x) = x2 – 36x – 12 f(x) = –x2 + 12x + 36 f(x) = –x2 – 12x – 36
Answer:
f(x) = –x^2 – 12x – 36
Step-by-step explanation:
The parent function, x^2, touches the x-axis at x=0. Translating it 6 units left replaces x with x-(-6) = x+6, so the function is ...
f(x) = (x+6)^2 = x^2 +12x +36
Reflecting the graph across the x-axis doesn't change the x-intercept, so Heather could be writing ...
f(x) = -x^2 -12x -36
It's D.
I have to have at least 20 characters.
Jeremy makes $57,852 per year at his accounting firm. How much is Jeremy’s monthly salary? (There are 12 months in a year.) How much is Jeremy’s weekly salary? (There are 52 weeks in a year.)
Answer:
Monthly: $4,821
Weekly: $1112.54
Step-by-step explanation:
Monthly
A monthly salary can be found by dividing the yearly salary by the number of months.
salary / months
His salary is $57,852 and there are 12 months in a year.
$57,852/ 12 months
Divide
$4,821 / month
Jeremy makes $4,821 per month.
Weekly
To find the weekly salary, divide the yearly salary by the number of weeks.
salary / weeks
He makes $57,852 each year and there are 52 weeks in one year.
$57,852 / 52 weeks
Divide
$1112.53846 / week
Round to the nearest cent. The 8 in the thousandth place tells use to round the 3 up to a 4 in the hundredth place.
$1112.54 / week
Jeremy makes $1112.54 per week
Which point is on the graph of f(x)=3.4x
Answer: The answer is (1, 12).
12 = 3 x 4^{1}
Step-by-step explanation: Hope it helps!
Answer:
Hi! The answer to your question is (1,12)
Step-by-step explanation:
The steps are:
I attached a picture to make sure if that’s the same problem as yours.
So in the picture you can see that there is option A, B, C, D
When we do A and B we will know that it is wrong
When we try C let’s see what we get!
When I did C I got 3.4₁ which equals to 12
Work:
Y=F [1] which equals to 3.4
3.4=12
So the answer will be C. (1,12)
Hope this helps! :)
if a varies inversely as the cube root of b and a=1 when b=64, find b
Answer:
b = 64/a³
Step-by-step explanation:
Using the given information, we can only find a relation between a and b. We cannot find any specific value for b.
Since a varies inversely as the cube root of b, we have ...
a = k/∛b
Multiplying by ∛b lets us find the value of k:
k = a·∛b = 1·∛64 = 4
Taking the cube of this equation gives ...
64 = a³b
b = 64/a³ . . . . . divide by a³
The value of b is ...
b = 64/a³
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:
Which best describes the relationship between the line that passes through the points (-9, 2) and (-5, 4) and the line that passes through the points (-3, 4) and (1, 6)?
Answer:
Parallel!
Step-by-step explanation:
If you put these points on a graph and connect the dots to be two lines, they are perfectly side to side :)
The graphs below have the same shape. What is the equation of the red
graph?
Step-by-step explanation:
If they have the same shape, the red graph is a translation of the blue, which is given to be y=x^2.
Since the red graph stays on the y axis at two units above the blue (y=x^2) curve, therefore the red curve is given by y=x^2+2.
The equation of the red graph is f(x) = x² + 2.
Option B is the correct answer.
What is an equation?An equation contains one or more terms with variables connected by an equal sign.
Example:
2x + 4y = 9 is an equation.
2x = 8 is an equation.
We have,
The graphs of f(x) = x² and f(x) = x² + 2 are both quadratic functions, which means they have a parabolic shape.
The graph of f(x) = x^2 is an upward-opening parabola with its vertex at the origin (0,0).
The parabola is symmetric about the y-axis and the x-axis.
The graph of f(x) = x² + 2 is also an upward-opening parabola, but it has been shifted upward by 2 units compared to the graph of f(x) = x².
This means that the vertex of the parabola has been shifted from (0,0) to (0,2).
Thus,
The equation of the red graph is f(x) = x² + 2.
Learn more about equations here:
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7.1 A player throws a fair die and simultaneously flips a fair coin. If the coin lands heads, then she wins twice, and if tails, then she wins one-half of the value that appears on the die. Determine her expected winnings.
Answer:
1.875
Step-by-step explanation:
To find the expected winnings, we need to find the probability of all cases possible, multiply each case by the value of the case, and sum all these products.
In the die, we have 6 possible values, each one with a probability of 1/6, and the value of each output is half the value in the die, so we have:
[tex]E_1 = \frac{1}{6}\frac{1}{2} + \frac{1}{6}\frac{2}{2} +\frac{1}{6}\frac{3}{2} +\frac{1}{6}\frac{4}{2} +\frac{1}{6}\frac{5}{2} +\frac{1}{6}\frac{6}{2}[/tex]
[tex]E_1 = \frac{1}{12}(1+2+3+4+5+6)[/tex]
[tex]E_1 = \frac{21}{12} = \frac{7}{4}[/tex]
Now, analyzing the coin, we have heads or tails, each one with 1/2 probability. The value of the heads is 2 wins, and the value of the tails is the expected value of the die we calculated above, so we have:
[tex]E_2 = \frac{1}{2}2 + \frac{1}{2}E_1[/tex]
[tex]E_2 = 1 + \frac{1}{2}\frac{7}{4}[/tex]
[tex]E_2 = 1 + \frac{7}{8}[/tex]
[tex]E_2 = \frac{15}{8} = 1.875[/tex]
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
A bread recipe calls for 2 1/2 cups of whole wheat flour 2/3 cups of rice flour 2 1/4 cups of white flour how many total cups of flour are needed write your answer as a simplified mixed number
Answer:
5 5/12
Step-by-step explanation:
you find the common denominator which is 12
2 6/12
8/12
2 3/12
now u add them all
hope this helps
Answer:
5 5/12 cups
Step-by-step explanation:
A pen in the shape of an isosceles right triangle with legs of length x ft and hypotenuse of length h ft is to be built. If fencing costs $ 2 divided by ft for the legs and $ 4 divided by ft for the hypotenuse, write the total cost C of construction as a function of h.
Answer
(4h/√2)+4h
Explanation:
the side length as a function of h will be needed, so we will compute it first,
Let x be the side length of the right isosceles triangle, then using Pythagorean theorem.
CHECK THE ATTACHMENT FOR DETAILED EXPLANATION
I NEED HELP PLEASE, THANKS! :)
A discus is thrown from a height of 4 feet with an initial velocity of 65 ft/s at an angle of 44° with the horizontal. How long will it take for the discus to reach the ground? (Show work)
Answer:
2.908 s
Step-by-step explanation:
The "work" is most easily done by a graphing calculator. We only need to tell it the equation of motion.
For speeds in feet per second, the appropriate equation for vertical ballistic motion is ...
h(t) = -16t² +v₀t +s₀
where v₀ is the initial vertical velocity in ft/s and s₀ is the initial height in feet. The vertical velocity is the vertical component of the initial velocity vector, so is (65 ft/s)(sin(44°)). We want to find t for h=0.
0 = -16t² +65sin(44°) +4
Dividing by -16 gives ...
0 = t^2 -2.82205t -0.2500
Using the quadratic formula, we find ...
t ≈ (2.82205 ±√(2.82205² -4(1)(-0.25))/2 ≈ 1.41103 +√2.24099
t ≈ 2.90802
It will take about 2.908 seconds for the discus to reach the ground.
_____
Comment on the question
You're apparently supposed to use the equation for ballistic motion even though we know a discus has a shape that allows it to "fly". It doesn't drop like a rock would.
what is the axis of symmetry of f(x)=-3(x+2)^2+4
Answer:
line passes through the vertex
Step-by-step explanation:
f(x)=-3(x+2)^2+4
x=-2 it is the x of the vertex
4 builders are building some new classrooms at Trinity. It takes them 5 months to build the classrooms. How long will it take 10 builders?
Answer:
it takes
[tex]\boxed {\red {2 \: \: months}}[/tex]
for 10 builders
Step-by-step explanation:
[tex]4 \: \: \: builders = 5 \: month \\ 10 \: builders = x[/tex]
Let us solve
[tex]4 = 5 \\ 10 = x[/tex]
so
[tex]4 = x \\ 10 = 5[/tex]
use cross multiplication
[tex]5 \times 4 = 10 \times x \\ 20 = 10x \\ \frac{20}{10} = \frac{10x}{10} \\ \green {x = 2}[/tex]
Answer:
[tex]\boxed{2months}[/tex]
Step-by-step explanation:
B1 = 4
M1 = 5
B2 = 10
M2 = x (we have to find this)
Since it is an inverse proportion (more builders will take less time and vive versa), we'll write it in the order of
=> B1 : B2 = M2 : M1
=> 4:10 = x : 5
Product of Means = Product of Extremes
=> 10*x = 4*5
=> 10x = 20
Dividing both sides by 10
=> x = 2 months
So, it will take 2 months to build classrooms by 10 builders.
Find the area of the irregular figure. Round to the nearest hundredth.
Answer:
23.14
Step-by-step explanation:
Solve for the area of the figure by dividing it up into parts. You can divide into a half-circle and a triangle
Half-Circle
The diameter is 6. This means that the radius is 3. Use the formula for area of a circle. Divide the answer by two since you only have a half-circle.
A = πr²
A = π(3)²
A = 9π
A = 28.274
28.274/2 = 14.137
Triangle
The base is 3 and the height 6. Use the formula for area of a triangle.
A = 1/2bh
A = 1/2(6)(3)
A = 3(3)
A = 9
Add the two areas together.
14.137 + 9 = 23.137 ≈ 23.14
The area is 23.14.
Answer:
23 sq. unitsStep-by-step explanation:
The figure consists of a semi circle and a triangle
Area of the figure = Area of semi circle + Area of triangle
Area of semi circle is 1/2πr²
where r is the radius
radius = diameter/2
radius = 6/2 = 3
Area of semi circle is
1/2π(3)²
1/2×9π
14.14 sq. units
Area of a triangle is 1/2×b×h
h is the height
b is the base
h is 6
b is 3
Area of triangle is
1/2×3×6
9 sq. units
Area of figure is
14.14 + 9
= 23.14
Which is 23 sq. units to the nearest hundredth
Hope this helps you.
Solve for x.
Simplify your answer as much as possible.
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:
Find the substance's half-life, in days.
Round your answer to the nearest tenth.
Answer:
t = 5.6 day
t =5 days 14 hours 24 minutes
Step-by-step explanation:
Half life is the time it will take for the original value or quantity I'd a particular substance to decrease by half of it's original self.
N = N•e(-kt)
N• = 25
K = 0.1229
Then
N = 25/2 = 12.5
The reason because at the half life , it's original value will decrease to half.
Let's solve for the half life t
N = N•e(-kt)
12.5 = 25e(-0.1229t)
12.5/25 = e(-0.1229t)
0.5 = e(-0.1229t)
In 0.5 =-0.1229t
-0.69314 = -0.1229t
-0.69314/-0.1229 = t
5.6399 = t
To the nearest tenth
5.6 days = t
Solve the system by graphing (Simplify your answer completely.)
Will someone please help me with this and give an explanation on how you got it? I don’t understand.
{x+y=8
{x-y=4
Answer:
(6,2)
Step-by-step explanation:
1) convert both equations to slope intercept form:
y=-x+8
and
y=x-4
now graph both equations separately by intercepts:
x int: 0=-x+8
-8=-x
8=x
y int: y=0+8
y=8
so the two coordinate points for first equation are (0,8) and (8,0)
lets move on two second equation: y=x-4
x int: 0=x-4
4=x
y int y=0-4
y=-4
so the 2 coordinate points are (4,0) and (0,4)
lets graph these two equations and see where they intersect:
(see graph below), the intersection is at (6,2) so (6,2) is our answer
hope this helps