Question

1. A sample of 61 students at a university were asked how many hours of sleep they get on weeknights. The sample had a mean of 6.2 hours and a standard deviation of 0.7 hours.

a. Use your calculator to construct a 95% confidence interval estimate for the mean reported weeknight sleep time among students at that university. Write a statement (we are...) that interprets your answer.

Answer 1

n= 61, = 6.2, s=0.7, c=95%

now we are using TI-83 Plus calculator, steps are as follows

1) Press button STAT

2) then navigate to TEST by using left arrow key

3) then scroll down to T INTERVAL and press button ENTER

4) now enter data as follows

5) scroll down to calculate and press ENTER you will get following answer

thus we get confidence interval as =  ( 6.0207 , 6.3793 )

Interpretation:

Therefore we are 95% confident that the mean weeknight sleep time among students

at that university lies between  6.0207 hours to   6.3793 hours