A school district is considering moving the start of the school day at Groveland High from 8:00 a.m. to 9:00 a.m. to allow students to get more sleep at night. They want to estimate how many more hours of sleep teens get if their school starts at 9:00 a.m. compared to teens whose schools start at 8:00 a.m. The district takes random samples of 50 of students from Groveland High and 39 students from Phillips High School, which starts at 9:00 a.m., and surveys them about their sleep habits. The sample mean number of hours of sleep per student at Groveland is 7.1 hours, and the standard deviation is 1.7 hours. At Phillips, the sample mean is 8.3 hours of sleep, with a standard deviation of 1.9 hours. What is the 90% confidence interval for the difference in mean hours of sleep for students at the two high schools

Answers

Answer 1

Answer:

The answer is "[tex]\bold{(7.1-8.3) \pm 1.665 \sqrt{\frac{(1.7)^2}{50}+\frac{(1.9)^2}{39}} }\\\\[/tex]"

Step-by-step explanation:

Given values:

[tex]\bar{x_1}=7.1\\\\\bar{x_2}=8.3\\\\s_1=1.7\\\\s_2=1.9\\\\n_1=50\\\\n_2=39[/tex]

Using formula:

[tex]\to (\bar{x_1} -\bar{x_2}) \pm t \sqrt{\frac{(s_1)^2}{n_1}+\frac{(s_1)^2}{n_2}} \\\\[/tex]

Put the values in the above formula:

[tex]\to (7.1-8.3) \pm 1.665 \sqrt{\frac{(1.7)^2}{50}+\frac{(1.9)^2}{39}} \\\\[/tex]


Related Questions

Andrew randomly selects a number from 1-15. What is the probability that the number he selects is an even number?

Answers

Answer:

7/15

Step-by-step explanation:

Probability= Number of even numbers / Total numbers

There are 7 even numbers between 1 and 15

P = 7/15

Mathematics challenge

Answers

Get the equation of the line containing PQ using the point-slope formula:

y - (-2) = 3/2 (x - (-6))

Solve for y to get it in slope-intercept form:

y = 3/2 x + 7

so the y-intercept is (0, 7).

The line containing QR is then

y - 7 = -3/4 (x - 0)

or

y = -3/4 x + 7

The point R is on the x-axis, so its y-coordinate is 0. Plug in y = 0 and solve for x to get the other coordinate:

0 = -3/4 x + 7

3/4 x = 7

x = 4/3×7 = 28/3

So the point R has coordinates (28/3, 0).

Answer:

Point R is on the x-axis, so its y-coordinate is 0. Plug in y = 0 and solve for x to get the other coordinate:

0 = -3/4 x + 7

Take off the zero...

3/4 x = 7

Answer

x = 4/3×7 = 28/3

And there it is

Point R has the coordinates (28/3, 0).

Step-by-step explanation:

Please help... I’ll give Brainliest ❤️

Answers

Answer:

triangle B is the reflection of triangle A across the x-axis


What is the value of g in the relative frequency table?
Round the answer to the nearest percent.
25%
33%
63%
68%

Answers

Answer:

g = 33%

Step-by-step explanation:

The values in the ends of the rows are found by adding together.

For the first row, we would add the value in cell AC to the value in AD to get the value in the corresponding column called "Total".  This means we add 20% +g to get 53%;

Subtract 20% from each side

g = 53% - 20%

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Answers

Answer:

BRAINLEST I LOVE M.INECRAFT R   O   B   L   O   X

Step-by-step explanation:

4. The measures of segment BS and segment PS are both 4.5 feet and m_PBS = 56°.

a. Find the measure of BSP. Item 2 says that “Angle QPS is supplementary to PSR."


b. Is BPS a unique triangle, or can more than one triangle be formed using the given segment
lengths and angle measures? Explain.

Answers

the answer to this is b

A car costs 12,000. During a sale, it will cost 10,920. By what percent was the price reduced?

Answers

Answer:

(12000 - 10920) / 12000 = 0.09

Step-by-step explanation:

PLS HELP!!

Given the diagram below, find the value of x.

The value of x is

Answers

Answer:

44°

Step-by-step explanation:

180-30-14=136

180-136

44

AABC is isosceles.
MZA = 48° and mZB = 4x + 4.
A
B
x= [?]


Answers

11 I hope that is on of your options

Identify the graph of the equation (x+3)2+(y+1)2=9

Answers

The resulting graph is a circle with center at (-3,-1) and radius 3.

The graph of the equation (x+3)²+(y+1)²=9

is a circle with center at (-3,-1) and radius 3. The equation of a circle with center (a,b) and radius r is given by the equation (x-a)² + (y-b)² = r². By comparing the given equation with the standard equation of a circle, we can easily see that the center of the circle is (-3,-1) and the radius is 3. To graph a circle, we need to first plot the center of the circle, which is (-3,-1) in this case. Next, we need to mark the radius of the circle, which is 3 units. We can do this by measuring 3 units from the center in any direction and marking the point. Since the radius of the circle is the same in all directions, we can repeat this process for other directions to get points on the circumference of the circle. We can use a compass to make this process easier. After plotting a sufficient number of points, we can draw a smooth curve passing through all the points to obtain the graph of the circle.

For more question  graph

https://brainly.com/question/5504986

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Jaheem had $15, but he spent $12 at the
bookstore. Which of the following represents the
amount Jaheem spent?
A. 0.08 or 8%
B. 0.8 or 8%
C. 0.08 or 80%
D. 0.8 or 80%

Answers

D. 0.8 or 80% Explanation: 12 divided by 15 is 0.8 which is equivalent to 80%

can someone please help me

Answers

Answer:

B/ The second one

Step-by-step explanation:

up down/down up= y axis

side to side= x axis

The triangles have the same coordinates if reflected across the y axis.

Have a wonderful day! May I have brainliest?

pls help!!

Bryant earns $15 in commission for every $150 worth of shoes that he sells. Which equation can be used to find the total commission, C, Bryant will earn if the cost, s, of the shoes he sells is known?

a) c= 1/15s
b) c=1/10s
c) 10s
d) c=15s

Answers

i think it’s d, but i’m not sure.

Please help
here the question
Rosalina just started a new job. She has $500 in her bank account. Every week, she deposits $40 into her bank account.

A)
Write an expression to represent how much Rosalina has in her account at any given time using x to represent the number of weeks.
I ALREADY SOLVED A BUT I NEED HELP WITH C

B) Rosalina wants to save $700 for the new smart tv write and equation to determine how many weeks (x) it will take for rosalina to have enough money to purchase her new tv

C) using your equation from b will rosalina have enough money for her new tv in four weeks?

also) how would the equation change if rosalina stopped working wasn't able to deposit $40 and had to instead withdraw $40 a week? Which part of your equation would change?

please help!

THANK YOU!!​

Answers

Answer:

Let M represent the amout at any time.

She saves $40 per week so total amount becomes 40x in any specified week.

where x is the number of weeks.

In the start she has $500 in her bank account so we 'll add this amount into the savings per week. So expression becomes

M = 40x+500

Simply put number of week in place of x and find the total amount.

Step-by-step explanation:

Answer:

for c it is no

Step-by-step explanation:

it is no because she deposits 40 a week, in 4 weeks she deposits 40x4=160, which is nowhere close to the 700 she needs. Even if you count the 500 in her account it is still no since it would total up to 660, not 700

1. A number cube is rolled 24 times and lands on 2 four times and on 6 three times.
a. Find the experimental probability of landing on a 2.
b. Find the experimental probability of not landing on a 6.
c. Compare the experimental probability you found in part a to its theoretical probability.
d. Compare the experimental probability you found in part b to its theoretical probability

Answers

Step-by-step explanation:

(A) you takeway 24 by 2 and add 6=28

You had $25 to spend on eight avocados.
After buying them you had $9. How
much did each avocado cost?

Answers

Answer:

Each avocado costs $2

Step-by-step explanation:

subtract 9 from 25 and get 16

divide 8 by 16 and you have $2


Factor the expression.
20b + 35 =
(Factor completely.)

Answers

Answer:

I think it would be 5(4b+7)

Step-by-step explanation:

I divided both terms by 5.

how do we pass maths​

Answers

Answer:

1- Create a Distraction Free Study Environment. Mathematics is a subject that requires more concentration than any other.  

2- Master the Key Concepts.  

3- Understand your Doubts.  

4- Apply Maths to Real World Problems.  

5- Practice, Practice and Practice even more.


What is the area of ADEF?

Answers

Answer:

6 sq ft

Step-by-step explanation:

Will someone please please help me

Answers

Answer:

Step-by-step explanation:

12 + 5 = 17

square root of 9 = 3

5 x 4 = 20

What is the area of the following figure in square inches?

Answers

Answer, Alright the formula for a Rectangle is (A = bh) so ill do ( 13 x 8 ) = 104. Next ill do the triangle 19 - 13 is 6 which is the height of the triangle. The formula for a triangle is ( 1/2bh ) so lets do (6 x 8 ) which is 48 now lets divide it by 2...24.

24 + 104 = 128

Step-by-step explanation:

First, I split the Square from the Traingle

Second, I did base times height which equaled  (104)

Third, I found the area of the triangle by base times height divided by 2.(24)

Lastly, I added the figures up which equaled 128


Enter the correct answer in the box.
Simplify the expression x^5•x^7

Answers

Answer:

x^12

Step-by-step explanation:

when multiplying with exponents, keep base and add exponents

when dividing with exponents, keep base and subtract exponents

Question 3(Multiple Choice Worth 4 points) (05.05)The width of a rectangle is shown below: A coordinate plane with a point A at negative 3, 3 and C at negative 3, negative 2. If the area of the rectangle to be drawn is 20 square units, where should points B and D be located if they lie to the right of points A and C? B(1, 3) and D(1, −2) B(3, 3) and D(3, −2) B(2, 3) and D(2, −2) B(1, 2) and D(1, −3)

Answers

D 4/147
FTC +65-/325
Junk. 5(-4)

Answer:

(3, 3) and D(3, −2

Step-by-step explanation:

A retail shop is replacing their flooring with laminate wood. The floor plan is shown below. Determine the total square feet of laminate wood needed to complete the the job.

Answers

Answer:

1075 ft

Step-by-step explanation:

25*35 = 875

8*25 = 200

875+200 = 1075

Rewrite 7^-2 using a positive exponent an evaluate the result.

Answers

positive exponent= 1/7^2
evaluate=1/49

combine like terms !-3r - 5 + 2r - 3r - 2s
HELP ASAP

Answers

Combine the r’s first:
3r + 2r - 3r = 2r
2s and 5 cannot combine because they don’t have the same variable after the number

Answer: 2r + 5 + 2s

3(4c + 5) = (3.4c) + (3.5) is an example of which property
a) Commutative property
b) Distributive property
c) Inverse Operation property
d) Multiplication property

Answers

Answer: B) Distributive property

Step-by-step explanation:

Definition:

- Commutative property: a+b=b+a

- Distributive property: a(b+c)=ab+ac

- Inverse operation property:

In Addition: a+(-a)=0In Multiplication: a×(1/a)=1

- Multiplication property: If a=b, a×c=b×c

Solve:

GIven

3(4c+5)=(3·4c)+(3·5)

This is distributive property because it is distributing 3 to each of the numbers in the parenthesis.

Hope this helps!! :)

Please let me know if you have any quesitons

What's the slop of the line with the two points 3,2 and 7,9

Answers

Answer and working out attached below. Hope this helps

Simplify 2a + 14 - 5a - 7 + 8a​

Answers

Step-by-step explanation:

2a -5a +8a.

2a +8a -5a

10a -5a = 5a

14-7=7

Answer=5a+7

HEY
so you need to collect like terms so

2a-5a+8a= 5a

5a+14-7

Then 14-7=7

The answer is

5a+7

0.9, 0.99, 0.09, 0.91, from least to greatest

Answers

Answer:

0.09, 0.9, 0.91, 0.99

Step-by-step explanation:

Well I'm in 7th grade so I already know this stuff

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