1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
maw [93]
3 years ago
13

A sports marketing company is interested in how many hours teenagers in a town spend watching sports. They randomly select 40 te

enagers in this town and ask how many hours per week they spend watching sports. The mean amount is 6.25 hours with a standard deviation of 4.33 hours. Which of the following is the 90% confidence interval for the true mean amount of time teenagers from this town watch sports?
Find the t-table here.

(4.396, 8.104)
(4.865, 7.635)
(5.097, 7.404)
(5.245, 7.256)
Mathematics
1 answer:
garri49 [273]3 years ago
5 0

Answer:

(5.097, 7.404)

Step-by-step explanation:

We have the standard deviation for the sample, which means that 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 = 40 - 1 = 39

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 39 degrees of freedom(y-axis) and a confidence level of 1 - \frac{1 - 0.9}{2} = 0.95. So we have T = 1.6849

The margin of error is:

M = T\frac{s}{\sqrt{n}} = 1.6849\frac{4.33}{\sqrt{40}} = 1.154

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 6.25 - 1.154 = 5.096 hours

The upper end of the interval is the sample mean added to M. So it is 6.25 + 1.154 = 7.404 hours.

The answer is  (5.097, 7.404)

You might be interested in
Change the following into mixed fraction 13/5​
Oduvanchick [21]

Answer:

2 3/5

Step-by-step explanation:

13/5​

5 goes into 13 2 time

2*5 =10

13-10 =3

There is 3 left over.  This goes over the denominator

2 3/5

7 0
3 years ago
Read 2 more answers
An airplane takes 3 hours to travel a distance of 1680 miles with the wind. The return trip was 4 hours against wind. Find the s
nasty-shy [4]

Answer:

Speed of plane in still air: 490  mile/hour

speed of wind: 70  mile/hour

Step-by-step explanation:

still speed = x        wind speed = w

with wind: speed = still + wind

(x+w) * 3 = 1680     ...a

against wind: speed = still - wind

(x-w) * 4 = 1680    ...b

b-a ... 4x-4w-3x-3w = 0

x-7w = 0

x = 7w

substitution: (7w+w)*3 = 1680      8w = 560       wind speed (w) = 70

still speed (x) = 7w = 490 mile/hour

5 0
3 years ago
The area of parallelogram is 60 ft2.The height is 5ft. How long is the base?
Lubov Fominskaja [6]

Answer:

b = 12 ft

Step-by-step explanation:

Given Data:

Height = h = 5 ft

Area = A = 60 ft^{2}  

To Find Out:

base = b =?

Formula:

A= b×h

b = A÷h

Solution:

b = A÷h

b = 60÷5

b = 12 ft

8 0
3 years ago
PLEASE HELP!!!!!!!
erastova [34]
Negative multiplied by a positive is a negative
(good thing happening to a bad guy is bad)
the answer is B
3 0
3 years ago
Read 2 more answers
Which inequality makes the statement below true? |-13 BLANK -13 O A. = O B. < OC. S O D. >
navik [9.2K]

Answer:

Hey there the best answer would be A.=

Step-by-step explanation:

3 0
3 years ago
Other questions:
  • Matthew ran 3/8 mile and then walked 7/10 mile. Which pair of fractions can he use to find how far he went in all? (A 15/40 and
    11·2 answers
  • Of the children at Molly's daycare, 1/8 are boys and 2/5 of the boys are under 1 year old. How many boys at the daycare are unde
    11·1 answer
  • Which is bigger two thirds or seven eights
    7·2 answers
  • The length of a rectangle is 4times the width. The perimeter is 90cm. Find the length and width
    12·1 answer
  • Becky took out an 80/20 mortgage on a $167,000 home. What is the amount
    9·2 answers
  • What is the equation of a line that passes through 0,5 and 4,8
    5·1 answer
  • The sum of 112cx, 3c, -12cx, and 70​
    8·1 answer
  • What is the total measure of an average man brain and heart
    15·1 answer
  • Aaron wishes to build an aquarium 12 inches long, 6 inches wide, and 8 inches high. The aquarium will be open at the top. He has
    15·1 answer
  • What ia 4(t-5) FAST !!!!!!
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!