A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 6 students' scores on the exam after completing the course: 6,16,19,12,15,14.
Using these data, construct a 90% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. Find the critical value that should be used in constructing the confidence interval.

Answers

Answer 1

Answer:

The critical value is [tex]T_c = 2.5706[/tex].

The 90% confidence interval for the average net change in a student's score after completing the course is (9.04, 18.30).

Step-by-step explanation:

Before building the confidence interval, we need to find the sample mean and the sample standard deviation:

Sample mean:

[tex]\overline{x} = \frac{6+16+19+12+15+14}{6} = 13.67[/tex]

Sample standard deviation:

[tex]s = \sqrt{\frac{(6-13.67)^2+(16-13.67)^2+(19-13.67)^2+(12-13.67)^2+(15-13.67)^2+(14-13.67)^2}{5}} = 4.4121[/tex]

Confidence interval:

We have the standard deviation for the sample, so the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 6 - 1 = 5

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 5 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 2.5706, that is, the critical value is [tex]T_c = 2.5706[/tex]

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.5706\frac{4.4121}{\sqrt{6}} = 4.63[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 13.67 - 4.63 = 9.04.

The upper end of the interval is the sample mean added to M. So it is 13.67 + 4.63 = 18.30.

The 90% confidence interval for the average net change in a student's score after completing the course is (9.04, 18.30).


Related Questions

Find the difference: -18 - (-18)

Answers

Answer:

0

Step-by-step explanation:

-18-(-18)

= -18+18 [(+) + (+)=(+)]

=0 [(-) + (-)=(-)]

State if the scenario involves a permutation or a combination. Then find the number of possibilities.

A team of 15 basketball players needs to choose two players to refill the water cooler.

Permutation/Combination:

Answer:

Answers

Answer:

Permutation ; 210 ways

Step-by-step explanation:

Permutation and combination methods refers to mathematical solution to finding the number of ways of making selection for a group of objects.

Usually, selection process whereby the order of selection does not matter are being treated using permutation, while those which takes the order of selection into cognizance are calculated using combination.

Here, selecting 2 players from 15 ; since order does not matter, we use permutation ;

Recall :

nPr = n! ÷ (n - r)!

Hence,

15P2 = 15! ÷ (15 - 2)!

15P2 = 15! ÷ 13!

15P2 = (15 * 14) = 210 ways

Question 3 of 28
What is the length of IN in the right triangle below?
M
19
N
O A. 442
B. 442
O c. 1200
D. 280

Answers

Answer:

Option C. √280

Step-by-step explanation:

From the question given above, the following data were obtained

MN = 19

ML = 9

LN =?

We can obtain the value of LN by using the pythagoras theory as illustrated:

M ² = ML² + LN²

19² = 9² + LN²

361 = 81 + LN²

Collect like terms

361 – 81 = LN²

280 = LN²

Take the square root of both side

LN = √280

Therefore, the length of LN is √280

Simplify: −4(b+6)−2b(1−4b

Answers

Step-by-step explanation:

-4b-24-2b+8b2

8b2-6b-24=0

Find the length of the arc. Round your answer to the nearest tenth​

Answers

Answer:

12.6 mi

Step-by-step explanation:

Arc length = 2πr (Θ/360)

2π(12) (60/360)

= 12.6 mi

Answered by g a u t h m a t h

It takes 12 people 15 hours to complete and certain job.how many hours would it take 18 people, working at the same rate to complete 2/5 of the same job?

Answers

Answer:

9 hours

Step-by-step explanation:

12 people take 15 hours to complete one job. First let's ask how long it would take 18 people working at the same rate to complete the same job? We can use proportions to answer this

[tex]\frac{12 people}{15 hours} = \frac{18 people}{x hours}\\x = \frac{18\times15}{12} = 22.5[/tex]

Now we know that one job takes 18 people 22.5 hours, so 2/5 of the job would take

[tex]\frac{18\times15}{12} \times \frac{2}{5} = 9[/tex]

Which of the following numbers has the greatest value?
89 3/4
66 1/2
55 2/3
74 1/4
106 5/6

Answers

Answer:

106 5/6

Step-by-step explanation:

55 < 66 < 74 < 89 < 106

the fractions are irrelevant because the whole numbers are all different

The greatest of the numbers will be 106 5/6 since 106 is greater than the rest of the integers present in the mixed fractions.

Finding greatest value in a sequence

The greatest value is the highest value in a given set of number.

Given the following numbers

89 3/4

66 1/2

55 2/3

74 1/4

106 5/6

The greatest of the numbers will be 106 5/6 since 106 is greater than the rest of the integers present in the mixed fractions.

Learn more on mixed fractions here: https://brainly.com/question/414559

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Which function has lowest rate of change?

5x – 2y = 15 (or) Cost of 5 pencils is 15 dollars

O Algebraic Function

O Verbal Description

Both the functions

O None of the choices

Answers

Answer:

A: Algebraic Function

Step-by-step explanation:

Algebraic function is given as;

5x – 2y = 15

Since we are dealing with rate of change, let's make y the subject first and find dy/dx.

Thus;

2y = 5x - 15

y = (5x/2) - 15/2

dy/dx = 5/2

dy/dx = 2.5

The verbal function is given as;

Cost of 5 pencils is 15 dollars

Thus, rate of 1 pencil = 15/5 = 3 pencils per dollar

We can see that the lowest rate of change is 2.5 and it is the algebraic function.

1. Write the polynomial function that models the given situation.A rectangle has a length of 12 units and a width of 11 units. Squares of x by x units are cut out of each corner, and then the sides are folded up to create an open box. Express the volume V of the box as a polynomial function in terms of x.
2. Write the polynomial function that models the given situation. A square has sides of 24 units. Squares x + 1 by x + 1 units are cut out of each corner, and then the sides are folded up to create an open box. Express the volume V of the box as a function in terms of x.
3. Write the polynomial function that models the given situation. A cylinder has a radius of x + 6 units and a height 3 units more than the radius. Express the volume V of the cylinder as a polynomial function in terms of x.

Answers

Answer:

1.  (12 - 2x)(11 - 2x)x

2. 4(11 - 2x)²(x + 1)

3. π(x³ + 15x² + 63x + 81)

Step-by-step explanation:

1. Write the polynomial function that models the given situation.

A rectangle has a length of 12 units and a width of 11 units. Squares of x by x units are cut out of each corner, and then the sides are folded up to create an open box. Express the volume V of the box as a polynomial function in terms of x.

Since the length of the rectangle is 12 units and its width 11 units and squares of x by x units are cut from its corners, it implies that a length x is cut from each side. So, the length of the open box is L = 12 - 2x and its width is w = 11 - 2x.

Since the cut corners of the rectangle are folded, the side x which is cut represents the height of the open box, h. so, h = x

So, the volume of the open box V = LWh = (12 - 2x)(11 - 2x)x

2. Write the polynomial function that models the given situation. A square has sides of 24 units. Squares x + 1 by x + 1 units are cut out of each corner, and then the sides are folded up to create an open box. Express the volume V of the box as a function in terms of x.

Since the square has sides of 24 units and squares of x + 1 by x + 1 units are cut from its corners, it implies that a length x + 1 is cut from each corner and the length 2(x + 1) is cut from each side. So, the length of side open box is L = 24 - 2(x + 1) = 24 - 2x - 2 = 24 - 2 - 2x = 22 - 2x = 2(11  - x)

Since the cut corners of the square are folded, the side x + 1 which is cut represents the height of the open box, h. so, h = x + 1

Since the area of the base of the pen box is a square, its area is L² = [2(11 - 2x)]²

So, the volume of the open box V = L²h = [2(11 - 2x)]²(x + 1) = 4(11 - 2x)²(x + 1)

3. Write the polynomial function that models the given situation. A cylinder has a radius of x + 6 units and a height 3 units more than the radius. Express the volume V of the cylinder as a polynomial function in terms of x.

The volume of a cylinder is V = πr²h where r = radius and h = height of cylinder.

Given that r = x + 6 and h is 3 units more than r, h = r + 3 = x + 6 + 3 = x + 9

So, V = πr²h

V = π(x + 3)²(x + 9)

V = π(x² + 6x + 9)(x + 9)

V = π(x³ + 6x² + 9x + 9x² + 54x + 81)

V = π(x³ + 15x² + 63x + 81)

Help on 3,5,7,9,11,13.15,17, please thank you

Answers

Answer:

3. 6a+60

5. 25+5w

7. 90-10t

11. 4.5-12c

13. f-2

15. 12z+1.5

Step-by-step explanation:

3.

6(a+10)

Multiply 6 by both factors in the parentheses, in this case, a and 10.

6*a = 6a

6*10 = 60

6(a+10) = 6a + 60

I only put the step- by- step explanation for #3, but you should be able to figure the rest out with that.

Explain how the given graph is deceptive.

Complete the statements based on the bar graph.

By not starting the horizontal axis at 0, the
bar appears to be about one-fourth the height of the Pecan bar. The
bar appears to be about one-half the height of the Pecan bar. The
bar appears to be less than one-half the height of the Pecan bar. This misleads the viewer to
the number of each type of nut used

Ans:

Pine Nut

Walnut

Almond

Understimate

Answers

Answer:

In the picture below.

Step-by-step explanation:

From the commenter and answer above, confirmed on edge 2022.

Factor.
64x^12 + 27y^3

Answers

Answer:

answer is (4x^4+3y)(16x^8-12x^4y+9y^2)

Step-by-step explanation:

You need to design a rectangle with a perimeter of 14.2 cm. The length must be 2.4 cm. What is the width of the
rectangle? (You might want to draw a picture.)

a) Let w = the width of the rectangle. Write the equation you would use to solve this problem.


b) Now solve your equation
* cm.
The width of the rectangle must be. Cm

Answers

Part (a)

Answer: 2(2.4+w) = 14.2

--------------

Explanation:

L = 2.4 = length

W = unknown width

The perimeter of any rectangle is P = 2(L+W)

We replace L with 2.4, and replace P with 14.2 to get 14.2 = 2(2.4+w) which is equivalent to 2(2.4+w) = 14.2

========================================================

Part (b)

Answer:   w = 4.7

--------------

Explanation:

We'll solve the equation we set up in part (a)

2(2.4+w) = 14.2

2(2.4)+2(w) = 14.2

4.8+2w = 14.2

2w = 14.2-4.8

2w = 9.4

w = 9.4/2

w = 4.7

The width must be 4.7 cm.

Solve 2x^2+5x+5=0 round solutions to the nearest hundredth.

Answers

Answer:

-0.56

Step-by-step explanation:

A factory makes twenty-three million, five hundred fifty candies each month. This number in standard form is

Answers

Answer:

23,000,550

Step-by-step explanation:

A million has six zeroes, so twenty three million is

23,000,000

Since five hundred fifty is not in the thousands, it replaces the last trio of zeroes.

We have the number in standard form as

23,000,550

Answer:

23000550

Step-by-step explanation:

Please Answer This!!! I NEEEDDD TOOO KNOWWWWW ANSWER!!!

Answers

Answer:

77.5

Step-by-step explanation:

Its rising at a constant rate between +10-15 each hour, so we if we were to add 25 or so to the 50, it would be close to 77.5, so I would assume the answer was B

HELP keep saying im getting wrong

instruction find the perimeter of the polygon​

Answers

Answer:

perimeter = 50

Step-by-step explanation:

Tangents to a circle from an external point are congruent , then

perimeter = (8 + 8) + (10 + 10) + (7 + 7) = 16 + 20 + 14 = 50

I need to know the answer ASAP

Answers

Answer:

Step-by-step explanation:

Need help pleaseeee!!!

Answers

Answer:

C is wrong!

Step-by-step explanation:

The explanation is in the picture!

!!I NEED THE ANSWER PLS!!
Which of the following represents the divisor and the dividend for the
synthetic division problem below?
- 3/ 2 4 -4 6
A. -3 and -2x2 - 4x2 + 4x-6
B. x+3 and -2x2 - 4x +47-6
C. X+3 and 2x + 4x2 - 4x+6
D. *-3 and 2x2 + 4x2 - 4x+6

Answers

Answer:

B

Step-by-step explanation:

B . x+3 and -2x2 - 4x +47-6

B . x+3 and -2x2 - 4x +47-6

The divisor and the dividend for the given synthetic division problem are : [tex]x+3[/tex] and [tex]2x^3+4x^2-4x+6[/tex]

What is synthetic division?

"It is a way of dividing one polynomial by another polynomial of first degree."

What is dividend?

"The value that is divided by another value to get the result. "

What is divisor?

"The value that divides another number either completely or with a remainder."

For given question,

We have been given a synthetic division problem.

- 3/ 2 4 -4 6

We need to represent the divisor and the dividend for the given synthetic division problem.

We know that, to perform synthetic division, here are the steps:

- The leading coefficient of the divisor should also be 1.

- Express the dividend in standard form.

- Write the leading coefficient in the dividend.

- Place the product of the number you brought down and the number in the division box in the preceding column.

- Write the result at the bottom of the row.

So, the divisor of the given synthetic division form would be,

x - (-3) = x + 3

And the dividend of the given synthetic division form would be,

There are four leading coefficient.

This means the dividend polynomial must be of degree 3.

From the leading coefficients 2 4 -4 6

[tex]2x^3+4x^2-4x+6[/tex]

Therefore, the divisor and the dividend for the given synthetic division problem are : [tex]x+3[/tex] and [tex]2x^3+4x^2-4x+6[/tex]

Learn more about the synthetic division here:

https://brainly.com/question/11850611

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What's the value of n if 13+19= n+25

Answers

32=n +25n= 32-25 = 7

.

.

..

.

.............

Answer:

[tex]13+19=n+25[/tex]

[tex]n+25=13+19[/tex]

Add 13+19= 32

[tex]n+25=32[/tex]

Now Subtract 25 from both sides

[tex]n+25-25=32-25[/tex]

[tex]n=7[/tex]

OAmalOHopeO

A study was conducted in order to estimate ?, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be ? = 3.6 hours.
A similar study conducted a year earlier estimated that ?, the mean number of weekly hours that U.S. adults use computers at home, was 8 hours. We would like to test (at the usual significance level of 5%) whether the current study provides significant evidence that this mean has changed since the previous year.
Using a 95% confidence interval of (7.7, 9.3), our conclusion is that:
a. the current study does provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls outside the confidence interval.
b. the current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls outside the confidence interval.
c. the current study does provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval.
d. the current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval.
e. None of the above. The only way to reach a conclusion is by finding the p-value of the test.

Answers

Answer:

d. the current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval.

Step-by-step explanation:

Mean was of 8 hours, test if it has changed:

At the null hypothesis, we test if it has not changed, that is, the mean is still of 8, so:

[tex]H_0: \mu = 8[/tex]

At the alternative hypothesis, we test if it has changed, that is, the mean is different of 8, so:

[tex]H_1: \mu \neq 8[/tex]

Using a 95% confidence interval of (7.7, 9.3), our conclusion is that:

8 is part of the confidence interval, which means that the study does not provide evidence that the mean has changed, and the correct answer is given by option d.

Which functions represent a vertical stretch of the parent function, f(x) = 1/x? Check all that apply.
g(x) = 3/x
g(x) = -2/x
g(x) = 1/4x
g(x) = 5/2x
g(x) = 1/2x

Answers

Answer:

[tex]g(x) = \frac{3}{x}[/tex]

[tex]g(x) =-\frac{2}{x}[/tex]

[tex]g(x) =\frac{5}{2x}[/tex]

Step-by-step explanation:

Given

[tex]f(x)=\frac{1}{x}[/tex]

Required

Which represents vertical stretch of f(x)

The transformation is represented as:

[tex]g(x) = a* f(x)[/tex]

Where:

[tex]|a| > 1[/tex]

So, the functions are:

[tex]g(x) = \frac{3}{x}[/tex] ---- [tex]|3| > 1[/tex]

[tex]g(x) =-\frac{2}{x}[/tex] --- [tex]|-2|>1[/tex]

[tex]g(x) =\frac{5}{2x}[/tex] --- [tex]|\frac{5}{2}| > 1[/tex]

Answer:

the other person is correct if you need them quick it is a b and d

Step-by-step explanation:

The American Management Association is studying the income of store managers in the retail industry. A random sample of 49 managers reveals a sample mean of $45,420. The standard deviation of the population is known to be $2,050.
a). Compute a 95% confidence interval, as well as the margin of error.
b). Interpret the confidence interval you have computed.

Answers

Answer:

a) The 95% confidence interval for the income of store managers in the retail industry is ($44,846, $45,994), having a margin of error of $574.

b) The interval mean that we are 95% sure that the true mean income of all store managers in the retail industry is between $44,846 and $45,994.

Step-by-step explanation:

Question a:

We have to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a p-value of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 1.96\frac{2050}{\sqrt{49}} = 574[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 45420 - 574 = $44,846.

The upper end of the interval is the sample mean added to M. So it is 45420 + 574 = $45,994.

The 95% confidence interval for the income of store managers in the retail industry is ($44,846, $45,994), having a margin of error of $574.

Question b:

The interval mean that we are 95% sure that the true mean income of all store managers in the retail industry is between $44,846 and $45,994.

Find the length of the segment indicated. circles 4

Answers

I need more information, comment on my "answer".

Trong một lớp học có $35$ sinh viên nói được tiếng Anh, $25$ sinh viên nói được tiếng Nhật trong đó có $10$ sinh viên nói được cả tiếng Anh và tiếng Nhật. Mỗi sinh viên trong lớp nói được ít nhất một trong hai: tiếng Anh hoặc tiếng Nhật. Hỏi sỹ số của lớp là bao nhiêu

Answers

Answer:

please write this question in English then I give answer

Determine the value of X. Please explain the answer

Answers

We have two lines from the same point.

These two lines are also tangents to same circle which implies that they are of the same length.

That is 2x - 1 = 9

2x = 9 +1 = 10

x =10/2

x = 5

On Monday, Main Street station sells 40 tickets.
There are four types of ticket; infant, child, adult and senior.
The bar chart shows the number of infant, child and adult tickets sold.

How many Senior tickets sold ?

Find how many adult tickets were sold than child tickets ?
BOTH QUESTIONS ANSWER NEEDED PLES HELP

Answers

Answer:

0 senior tickets were sold

5 more adult tickets were sold than chil tickets

Step-by-step explanation:

You need to see the frequency of each bar

Answer by Gauthmath

Please help I need this done ASAP
10 points + crown for whoever has the most accurate answer

Answers

Part a)

Time:distance

1:3

Part b)

6 hours

Part C)

81km

Answered by Gauthmath must click thanks and mark brainliest

I NEED HELP PLEASE!!!!

Answers

Answer:

the answer to that's is B bud

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