A Group of Statistics Students Decided to Conduct a Survey

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 standard deviation of 6
Hours, what is the required sample size if the error is to be less than ½ hour with a 95% level of
Confidence?

A) 554
B) 130
C) 35
D) 393