Find the minimum sample size n needed to estimate mu to with

Find the minimum sample size n needed to estimate mu to within 26, with a 99% level of confidence. (Use s = 276.)

Solution

s = 276

mu is not given

Margin of error is within 26

This implies 276(2.58)/rtn =26

or rt n = 27.39

n >= 750.15

i.e. Sample size should be atleast 751.