Question

25 randomly selected students took a survey on how long they spent on social media. The...

25 randomly selected students took a survey on how long they spent on social media. The mean number of minutes these students spent on social media was 205.1 minutes with a standard deviation of 150 minutes.The population of the time spent on social media is normally distributed. Construct a 98%confidence interval for the population standard deviation of the time students spend on social media.

Homework Answers

Answer #1

df = 15 - 1 = 24

T score for 98% confidence interval = t24,0.01 = 2.492

Confidence interval

                              

                              

                               = (130.34 , 279.86)

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A survey of 20 randomly selected adult men showed that the mean time they spend per...
A survey of 20 randomly selected adult men showed that the mean time they spend per week watching sports on television is 9.34 hours with a standard deviation of 1.34 hours. Assuming that the time spent per week watching sports on television by all adult men is (approximately) normally distributed, construct a 90 % confidence interval for the population mean,   μ . Round your answers to two decimal places. Lower bound: Enter your answer; confidence interval, lower bound Upper bound:...
According to a social media​ blog, time spent on a certain social networking website has a...
According to a social media​ blog, time spent on a certain social networking website has a mean of 18 minutes per visit. Assume that time spent on the social networking site per visit is normally distributed and that the standard deviation is 4 minutes. If you select a random sample of 100 sessions, what is the probability that the sample mean is between 17.5 and 18.5 minutes?
Nine randomly selected teens were asked how many hours per day they spend interacting with others...
Nine randomly selected teens were asked how many hours per day they spend interacting with others through social media, such as Instagram and Snapchat. The mean time was 4.8 hours and the standard deviation was 1.4 hours. Find the 90% confidence interval for the mean time. Assume this variable is normally distributed
A survey was taken of 28 students about how long they spend on PSY 230 homework....
A survey was taken of 28 students about how long they spend on PSY 230 homework. The results were approximately normally distributed with a mean of 13 hours and a standard deviation of 2 hours. Construct a confidence interval at 90%. Round your answers to two decimal places. _______ +/- _________
A survey of 87 randomly selected homeowners finds that they spend a mean of $65 per...
A survey of 87 randomly selected homeowners finds that they spend a mean of $65 per month on home maintenance. Assume that the population standard deviation is $13 per month. Construct and interpret a 97% confidence interval for the mean amount of money spent per month on home maintenance by all homeowners.
A survey of 90 randomly selected homeowners finds that they spend a mean of $66 per...
A survey of 90 randomly selected homeowners finds that they spend a mean of $66 per month on home maintenance. Assume that the population standard deviation is $13 per month. Construct and interpret a 95% confidence interval for the mean amount of money spent per month on home maintenance by all homeowners.
According to a social media​ blog, time spent on a certain social networking website has a...
According to a social media​ blog, time spent on a certain social networking website has a mean of 16 minutes per visit. Assume that time spent on the social networking site per visit is normally distributed and that the standard deviation is 5 minutes. If you select a random sample of 36 ​sessions, what is the probability that the sample mean is between 15.5 and 16.5 minutes? (Round your answer to three decimal places)
A survey of 100 randomly selected Michigan residents finds that the they spend a mean of...
A survey of 100 randomly selected Michigan residents finds that the they spend a mean of $21 per month on going to the movies. An independent study of a 100 randomly selected California residents find that they spend a mean of $46 per month on going to the movies. Assume that the population standard deviation for the Michigan residents is $5 per month and that the population standard deviation for the California residents is $23 per month. Answer the following...
Thirty randomly selected students took the calculus final. If the sample mean was 77 and the...
Thirty randomly selected students took the calculus final. If the sample mean was 77 and the standard deviation was 11.9, construct a 99% confidence interval for the mean score of all students. Round your answer in 2 decimal places
A survey of 100 randomly selected Michigan homeowners finds that they spend a mean of $67...
A survey of 100 randomly selected Michigan homeowners finds that they spend a mean of $67 per month on home maintenance. In an independent survey, 100 randomly selected Florida homeowners find that they spend a mean of $75 per month on home maintenance. Construct a 99% confidence interval for the true difference in the mean amounts of money spent per month on home maintenance for the two states. Assume that the population standard deviation is $14 per month for Michigan...