A group of statistics students decided to conduct a survey a

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of 8 hours, what is the required sample size if the error should be less than 0.5 hour with a 95% level of confidence?

Solution

Given a=1-0.95=0.05, Z(0.025) = 1.96 (from standard normal table)

So n=(Z*s/E)^2

=(1.96*8/0.5)^2

=983.4496

Answer: 984