Grades on a standardized test are known to have a mean of 1000 for students in the United States. The test is administered to 453 randomly selected students in Florida; in this sample, the mean is 1013 and the standard deviation (5) is 108.

a. Construct a 95 % confidence interval for the average test score for Florida students.
b. Is there statistically significant evidence that Florida students perform differently than other students in the United States?
c. Another 503 students are selected at random from Florida. They are given a 3-hour preparation course before the test is administered. Their average test score is 1019 with a standard deviation of 95.
i. Construct a 95% confidence interval for the change in average test score associated with the prep course.
ii. Is there statistically significant evidence that the prep course helped?

d. The original 453 students are given the prep course and then are asked to take the test a second time. The average change in their test scores is 9 points, and the standard deviation of the change is 60 points.
i. Construct a 95% confidence interval for the change in average test scores.
ii. Is there statistically significant evidence that students will perform better on their second attempt after taking the prep course?
iii. Students may have performed better in their second attempt because of the prep course or because they gained test- taking experience in their first attempt. Describe an experiment that would quantify these two effects.

Answers

Answer 1

Answer:

a. The 95% confidence interval is 1,022.94559 < μ < 1,003.0544

b. There is significant evidence that Florida students perform differently (higher mean) differently than other students in the United States

c. i. The 95% confidence interval for the change in average test score is; -18.955390 < μ₁ - μ₂ < 6.955390

ii. There are no statistical significant evidence that the prep course helped

d. i. The 95% confidence interval for the change in average test scores is  3.47467 < μ₁ - μ₂ < 14.52533

ii. There is statistically significant evidence that students will perform better on their second attempt after the prep course

iii. An experiment that would quantify the two effects is comparing the result of the confidence interval C.I. of the difference of the means when the student had a prep course and when the students had test taking experience

Step-by-step explanation:

The mean of the standardized test = 1,000

The number of students test to which the test is administered = 453 students

The mean score of the sample of students, [tex]\bar{x}[/tex] = 1013

The standard deviation of the sample, s = 108

a. The 95% confidence interval is given as follows;

[tex]CI=\bar{x}\pm z\dfrac{s}{\sqrt{n}}[/tex]

At 95% confidence level, z = 1.96, therefore, we have;

[tex]CI=1013\pm 1.96 \times \dfrac{108}{\sqrt{453}}[/tex]

Therefore, we have;

1,022.94559 < μ < 1,003.0544

b. From the 95% confidence interval of the mean, there is significant evidence that Florida students perform differently (higher mean) differently than other students in the United States

c. The parameters of the students taking the test are;

The number of students, n = 503

The number of hours preparation the students are given, t = 3 hours

The average test score of the student, [tex]\bar{x}[/tex] = 1019

The number of test scores of the student, s = 95

At 95% confidence level, z = 1.96, therefore, we have;

The confidence interval, C.I., for the difference in mean is given as follows;

[tex]C.I. = \left (\bar{x}_{1}- \bar{x}_{2} \right )\pm z_{\alpha /2}\sqrt{\dfrac{s_{1}^{2}}{n_{1}}+\dfrac{s_{2}^{2}}{n_{2}}}[/tex]

Therefore, we have;

[tex]C.I. = \left (1013- 1019 \right )\pm 1.96 \times \sqrt{\dfrac{108^{2}}{453}+\dfrac{95^{2}}{503}}[/tex]

Which gives;

-18.955390 < μ₁ - μ₂ < 6.955390

ii. Given that one of the limit is negative while the other is positive, there are no statistical significant evidence that the prep course helped

d. The given parameters are;

The number of students taking the test = The original 453 students

The average change in the test scores, [tex]\bar{x}_{1}- \bar{x}_{2}[/tex] = 9 points

The standard deviation of the change, Δs = 60 points

Therefore, we have;

C.I. = [tex]\bar{x}_{1}- \bar{x}_{2}[/tex] + 1.96 × Δs/√n

∴ C.I. = 9 ± 1.96 × 60/√(453)

i. The 95% confidence interval, C.I. = 3.47467 < μ₁ - μ₂ < 14.52533

ii. Given that both values, the minimum and the maximum limit are positive, therefore, there is no zero (0) within the confidence interval of the difference in of the means of the results therefore, there is statistically significant evidence that students will perform better on their second attempt after the prep course

iii. An experiment that would quantify the two effects is comparing the result of the confidence interval C.I. of the difference of the means when the student had a prep course and when the students had test taking experience


Related Questions

Which whole number is equivalent to 12/3 ?

Answers

Answer:

4

Step-by-step explanation:

12 divided by 3 is 4. It's that simple!

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Answer:

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Step-by-step explanation:

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The height y (in feet) of a ball thrown by a child is
Y=-1/12x^2+2x+3
where x is the horizontal distance in feet from the point at which the ball is thrown.
(a) How high is the ball when it leaves the child's hand?
feet
(b) What is the maximum height of the ball?
feet
(c) How far from the child does the ball strike the ground?
feet

Answers

Answer:

Step-by-step explanation:

Reflection over y=1
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Answer:

reflect over what axis y or x?

Given the following prices and unit conversions, rank the brands from lowest to highest unit price.
Brand A: $1.48 for 2.5 pounds
Brand B: $1.30 for 907.18 grams; 1 pound is approximately 453.59 grams
Brand C: $1.55 for 50 ounces; 1 pound is equal to 16 ounces
a.
Brand A, Brand B, Brand C
b.
Brand A, Brand C, Brand B
c.
Brand B, Brand A, Brand C
d.
Brand C, Brand A, Brand B

Answers

Answer:

d.

Brand C, Brand A, Brand B

Step-by-step explanation:

To find the unit price, we divide the price by the number of pounds.

Brand A: $1.48 for 2.5 pounds

Unit price of:

[tex]\frac{1.48}{2.5} = 0.592[/tex]

Brand B: $1.30 for 907.18 grams; 1 pound is approximately 453.59 grams

907.18/453.59 = 2 pounds

Unit price of:

[tex]\frac{1.3}{2} = 0.65[/tex]

Brand C: $1.55 for 50 ounces; 1 pound is equal to 16 ounces

50/16 = 3.125 pounds

Unit price of:

[tex]\frac{1.55}{3.125} = 0.496[/tex]

From lowest to highest unit price:

C, A and B, so option d.

Answer:

D

Step-by-step explanation:

Unit prices are ratios, so you can add the two prices together and divide by the smaller unit price to get a usable number.

Natalia can serve 120 volleyballs in 8 minutes and 330 volleyballs in 22 minutes. How many volleyballs can Natalia serve per minute if she is serving at a constant rate?

Answers

Answer:

15

Step-by-step explanation:

120+330=450

8+22=30

per minute->450÷30=15


The atmospheric pressure p on a balloon or an aircraft decreases with increasing height. This pressure, measured in milimeters of mercury, is related to the heighth (in kilometers) above sea level by the formula p = 760 -0.145
(a) Find the height of an aircraft if the atmospheric pressure is 246 millimeters of mercury

Answers

Answer:

[tex]h = 3544.83km[/tex]

Step-by-step explanation:

Given

[tex]P= 760 - 0.145h[/tex]

Required

Find h when P = 246

Substitute 246 for P

[tex]246= 760 - 0.145h[/tex]

Collect like terms

[tex]246- 760 = - 0.145h[/tex]

[tex]-514= - 0.145h[/tex]

Make h the subject

[tex]h = \frac{-514}{-0.145}[/tex]

[tex]h = 3544.83km[/tex]

Pls pls help me I will mark you brainest

Answers

y values: 3,4,5,6

x values: 5,10,15,20

Step-by-step explanation:

I used a graphing calculator but y is increasing by one and x increases by 5 each time

Answer:

See below.

Step-by-step explanation:

A's number is x. B's number is y.

x = 5y - 10

First row: What is x when y= 3?

                             x = 5y - 10 = 5*3 - 10 = 15 - 10 = 5; x = 5

Second row: What is x when y = 4?

                             x = 5y - 10 = 5*4 - 10 = 20 - 10 = 10; x = 10

Third row:      What is y when x = 15?

                             x = 5y - 10

  Add 10 both sides     x + 10 = 5y - 10 +10

                                      x + 10 = 5y

But we're told x = 15, so   15 + 10 = 5y

                                             25 = 5y

Divide both sides by 5         25/5 = 5y/5

                                                  5 = y                      y = 5

Fourth row: What is x when y = 6?

                                        x = 5y - 10 = 5*6 - 10 = 30 - 10 = 20; x = 20

                       

Simplify the expression below! The picture is down below!

Answers

Answer:

Its C

Step-by-step explanation:

A necklace and earrings cost $144. Six necklaces and five pairs of earrings cost $825

Answers

Step-by-step explanation:

let necklace : x

let earrings : y

x+y=144 -1st eqn

6x+5y=825 -2nd eqn

y=144-X -3rd eqn

substitute eqn into 2nd eqn

6x+5(144-x)= 825

6x +720-5X =825 (expanded)

X = 825-720

X =105

substitute "X=105" into 1st eqn

(105)+y=144

y= 144-105

y=39

1 necklace = 105$

1 pair of earrings = 39$

(to check back: substitute the value into the original eqn)

Trey has plastic cubes stored in a box that measures 4 ft long,
,22
ft wide, and 2 ft tall.
The edge length of each plastic cube is
1
1
2
ft.
How many plastic cubes can fit into the box?
20 plastic cubes
45 plastic cubes
125 plastic cubes
160 plastic cubes

Answers

160 plastic cubes. I believe

Answer:

160 Cubes :)

Step-by-step explanation:

a storage jug was 4/5 full of water when did get indicated 72 what was the full capacity of the storage jug​

Answers

Answer:

90. ( was the full capacity of jug)

to solve this

firstly let the full capacity of jug

be. x

so,

4/5*x = 72

x = 72*5/4

x = 90

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Answers

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what is a formula for the nth term of the given sequence?

12,6,3...

Answers

Given:

The sequence is:

12, 6, 3, ...

To find:

The formula for the nth term of the given sequence.

Solution:

We have,

12, 6, 3, ...

Here, first term is 12.

Clearly, [tex]\dfrac{6}{12}=\dfrac{3}{6}[/tex]. Since the given sequence has a common ratio [tex]r=dfrac{1}{2}[/tex], therefore it is a geometric sequence.

The formula for the nth term of the given sequence is:

[tex]a_n=ar^{n-1}[/tex]

Where, a is the first term and r is the common ratio.

[tex]a_n=12\left(\dfrac{1}{2}\right)^{n-1}[/tex]

Therefore, the formula for the nth term of the given sequence is [tex]a_n=12\left(\dfrac{1}{2}\right)^{n-1}[/tex].

Answer:

Step-by-step explanation:

You open an account at Bertha’s Banking Branch. You put $50 in the bank and your account earns $4 per week in interest. How many weeks will it take for the balance in your account to be $90?

Answers

Answer:

10

Step-by-step explanation:

50+4x=90

4x=90-50

4x=40

x=40/4

x=10

I don’t know I think u times both of them 40 and 36 then divide by 4 then times by 2 i don’t know

Answers

What is the question?

Find the area of the circle. Use 3.14 for .
20 yd

Answers

ANSWER:
314 yd^2

Explanation:
Use the formula for the area of the circle. Since the diameter is 20, the radius is 20/2=10

Answer:

314 yd²

Step-by-step explanation:

A = πr²

 Use the formula.

A = π(10)²

 Substitute. Use 10 for r.

A ≈ 3.14 × 10²

 Substitute. Use 3.14 for π.

A ≈ 3.14 × 100 Evaluate the power.

A ≈ 314 Multiply.

The area of the circle is about 314 yd².

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Answers

Answer:

C. 3 to 18, 5 to 30 is equal

Step-by-step explanation:

There is 1/4 of a birthday cake left over. If 4 friends share it equally, what fraction of the cake will each friend receive? ( test please hurry!)

Answers

Answer:

The awnser is 1/16!!!!!!!!!!!!!

Find the value of x in the following figure

Answers

I think it’s 90 just add them up the subtract 180




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Also can you explain how you got your answer

Answers

Answer:

i think its 15,6,7,45

Answer:

Down Below :)

Step-by-step explanation:

15, 6, 7, 45

Multiply 5 by 1. You should get 5. Multiply/Divide. Top to Bottom is Multiplication, meanwhile Bottom to top is Division. Hope this helped!

What is the solution to this equation?
2x + x - 11 + 3 - 7x = 15
O -
A. x=-1
O B. - 13
O cx
O D. - 23
C. x=23

Answers

Answer:

Step-by-step explanation:

2x + x - 11 + 3 - 7x = 15

-4x = 23

x = -23/4

During tug of war, team A pulls to the East with 24N of force and team B pulls to the West with 32N of force. Which team will win and what is the net force?
Team B, 8N

Team B, 56N

Team A, 56N

Team A, 8N

Answers

Answer: Team B, 8N

Step-by-step explanation: I think it's team be because when doing the problem team a is 24 n to the right while Team B is 32 n to the left, and since they are pointing different directions you would subtract those and then get your answer. Since Team B has the larger force it will be the one to win.

What would measure a be?

Answers

Answer:

a = 40 degrees

Step-by-step explanation:

the inscribed angle of 200 degree arc is 100 degrees.

the sum of all the interior angles of a triangle is 180 degrees so:

angle a = 180 - 100 - 40 = 40 degrees

Two students are reading a novel. Ashley reads 10 pages per day. Carly reads 8 pages per day, but she starts
early and is already on page 40.

d=days
p=pages

Ashley: p=10d
Carly: p=8d+40

On day ____, both girls should be on page ____.

Answers

Answer:

On day 20, they should both be on page 200

Step-by-step explanation:

I set the 2 equations up:

10d=8d+40 and then subtracted 8d from both sides

2d=40 and then divided both sides by 2

d=20

I then took 20 and multiplied it by 10 for Ashley (200) and then multiplied it by 8 for Carly (160) and added 40 (200)

Hope this helps!

6
6
4
1 5
-8
If A = 7
-4
and B = | 9
-5 -8
find 3A + 9B.

Answers

Answer:

456yup 89i28993728128828282 6r3235

664r5790

what is the answer of this:
689 × 6156 ÷ 18% of 684 = 28 × 250 ÷ 8 + ? + 4300
A)27295
B)29275
C)29527
D)29725
E)None of these

Answers

Answer:

1606588.92

Step-by-step explanation:

2/4+3/2+1/4 I need help

Answers

Answer:

2 1/4 or 2.25

Step-by-step explanation:

2/4 = 1/2

3/2 = 6/4

1/2 + 3/2 + 1/4

2/4 + 6/4 + 1/4

add

2 + 6 + 1

= 9

so

9/4, = 2 1/4

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Which expression is equivalent to sec^2x

Answers

The trig function sec^2 x can also be expressed as 1 - csc^2 x. Both mean the same thing.

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