Question

In: Statistics and Probability

In a survey of 28 teenagers who were asked how many hours per week they spend...

In a survey of 28 teenagers who were asked how many hours per week they spend watching T.V., the sample mean was 13 hours and the population standard deviation is 5.8 hours. Find a 99% Confidence Interval for the population mean number of hours teenagers watch T.V.

Write the interval below. Write a sentence interpreting this. (Round answer to 2 decimal places)

Solutions

Expert Solution

Solution :

Given that,

Point estimate = sample mean = = 13

Population standard deviation =    = 5.8
Sample size = n =28

At 99% confidence level the z is ,

  = 1 - 99% = 1 - 0.99 = 0.01

/ 2 = 0.01 / 2 = 0.005

Z/2 = Z0.005 = 2.576   ( Using z table )

Margin of error = E = Z/2* ( /n)

= 2.576 * (5.8 / 28)

= 2.82

At 99% confidence interval estimate of the population mean is,

- E < < + E

13-2.82 < <13+2.82

10.18< < 15.82

sample mean lies between thease two intervals 10.18 to 15.82

orchestra answered 1 year ago
Next > < Previous

Related Solutions

When a survey​ asked, "About how many hours per week do you spend sending and answering​...
When a survey​ asked, "About how many hours per week do you spend sending and answering​ e-mail?" the 7 females in the survey sample of age at least 80 had the following responses. Use the data to complete parts a through c. 0 0 3 4 6 8 13 a. Using​ technology, find the sample​ mean, standard​ deviation, and the standard error of the sample mean. The sample mean is 4.86. ​(Round to two decimal places as​ needed.) The sample...
When a survey​ asked, "About how many hours per week do you spend sending and answering​...
When a survey​ asked, "About how many hours per week do you spend sending and answering​ e-mail?" the 7 females in the survey sample of age at least 80 had the following responses. Use the data to complete parts a through c. 0 0 1 2 8 10 15 a. Using​ technology, find the sample​ mean, standard​ deviation, and the standard error of the sample mean. The sample mean is 4.86. ​(Round to two decimal places as​ needed.) The sample...
In a survey, students are asked how many hours they in a typical week. A five...
In a survey, students are asked how many hours they in a typical week. A five number summary of the responses is 4,5,8,12,20. Which interval describes the number of hours spent studying in a typical week for about 25% of the students sampled?
In a class survey, students are asked how many hours they sleep per night. In the...
In a class survey, students are asked how many hours they sleep per night. In the random sample of 18 students, the (sample) mean is 6.8 hours with a (sample) standard deviation of 1.9 hours. We wish to know if this shows that the class’s student population on average has not gotten at least the recommended 8 hours of sleep at the α = .1 level. The distribution of sleep for this population follows a normal distribution. c) Please use...
In a survey, 100 adults in a certain country were asked how many hours they worked...
In a survey, 100 adults in a certain country were asked how many hours they worked in the previous week. Based on the results, a 95% confidence interval for mean number of hours worked was lower bound: 30 hours and upper bound: 38 hours. Which of the following represents a reasonable interpretation of the result? For those that are not reasonable, explain the flaw. Interpretation #1: There is a 95% chance the mean number of hours worked by adults in...
Exercise 3. In a class survey, students are asked how many hours they sleep per night....
Exercise 3. In a class survey, students are asked how many hours they sleep per night. In the sample of 22 students, the (sample) mean is 6.77 hours with a (sample) standard deviation of 1.472 hours. We wish to know if this shows that the class’s student population on average has not gotten at least the recommended 8 hours of sleep at the α = .1 level. The distribution of sleep for this population follows a normal distribution. a. Write...
I am curious about how many hours per week my students spend on their online coursework....
I am curious about how many hours per week my students spend on their online coursework. So, I surveyed 9 of my students on how many hours per week they spend on my online PSY 230 course. According to a survey of online college students (in all courses), students studied an average of 9 hours a week for a 3-credit course. I assume that the national study time scores are normally distributed, and I set the significance level at α...
A random sample of 76 teenagers were asked how many movies they see in a year....
A random sample of 76 teenagers were asked how many movies they see in a year. It came out that the mean number of movies-per-year is 51.2 and the standard deviation is 15.4. Use a .05 significance level to test the claim that the mean number of movies-per-year is 52. Test claim using the critical value method .
The 2014 General Social Survey asked randomly selected 1475 subjects how many hours per day they...
The 2014 General Social Survey asked randomly selected 1475 subjects how many hours per day they watched TV, on average. We want to test whether there are differences in population means according to the marital status of the subject. The data set TVdata contains three variables (TVhours, status). a) identify the explanatory variable and response variable and explain why
In a survey, 23 people were asked how much they spend on their child’s last birthday...
In a survey, 23 people were asked how much they spend on their child’s last birthday gift. The results were roughly bell-shaped with a mean of $37 and standard deviation of $2. Find the margin of error at an 80% confidence level. Find the confidence interval and give a complete confidence statement. Round to 2 decimal places.
ADVERTISEMENT
Subjects
ADVERTISEMENT
Latest Questions
ADVERTISEMENT