The table shows the results of two 7th grade surveys that Roddy took to find out how many

hours of sleep 7th graders at his school get on

a typical school night:

Based on the sample data, which of the following

is the closest to the mean number of hours of

sleep a 7th grade student gets?

Group of answer choices

8

7

8.25

7.75

Given a normal distribution with µ =50 and σ =4, what is the probability that 5% of the values are less than what x values? between what two x values (symmetrically distributed around the mean) are 95 % of the values? instructions: show all your work as to how you have reached your answer. don’t simply state the results. show graphs where necessary.