Question

Addicted to the Internet?The Ann Arbor public school officials would like to estimate the population mean daily Internet usage time for all Ann Arbor teens. To do so, a large random sample of Ann Arbor teens was selected. Here are the results of their study. The 95% confidence interval for the mean daily internet usage time for the population of all such Ann Arbor teens was found to be (6.7 hours, 9.3 hours).The 99% confidence interval or the mean daily internet usage time for the population of all such Ann Arbor teens was found to be (6.257 hours, 9.743 hours).The Ann Arbor public school officials know that you have some statistical background and would like your opinion. Please read each statement carefully and share with us your opinion.

Answer 1

Answer:

We can assure the Ann Arbor officials that after look the information we conclude that the mean is 8 h

Step-by-step explanation:

From CI ( 95 % )  = ( 6,7 ; 9,3 )

And the information "large random size sample" we conclude that the population has a normal distribution; a normal distribution has a bell shape curve, and data must spread symmetrically with respect to the mean, therefore the mean is:

6,7 + 9,3 = 16

16/2 = 8

If we need t check we can use the other CI

CI ( 99 % ) = (6,257 , 9,743 )

6,257 + 9,743 = 16

16/2 = 8

We are sure the mean is 8 h