part a) the daily sleep duration among high school students is normall distributed with a mean of 7.13 hours and standar

[answerhappygod]

part a) the daily sleep duration among high school students is
normall distributed with a mean of 7.13 hours and standard
deviation of 1.67 hours , if you plan to take an SRS of of size 60
whats the standard deviation of your sleep time?
part b) the sleep duration among duke students is normall
distributed with a mean of 7.13 and standard deviation of 1.67
hours , you want to use a sample size such that 95% of the averages
fall within + or - 15 (0.25 of an hour) of the true mean of 7.13
hours , determine the smallest number of students you would need to
sample?