The mean percentage of a population of people eating out at least once a week is 57% with a standard deviation of 3.5%. Assume that a sample size of 40 people was surveyed from the population an infinite number of times.
95% of the sample mean occurs between what two percents?

Question

The mean percentage of a population of people eating out at least once a week is 57% with a standard deviation of 3.5%. Assume that a sample size of 40 people was surveyed from the population an infinite number of times.
95% of the sample mean occurs between what two percents?

perl · Answer

Did you try anything so far?

17jeisaac · Answer

I did 57+1.96*3.5/sqrt of 40 and then I did 57-1.96*3.5/sqrt of 40 but the choices don't have the numbers I got.

perl · Answer

did you get 
(55.915, 58.085) ?