Please help me learn the steps to finding the answer.

How large a sample would the researcher need to estimate the mean body temperature to within 0.1 degrees with 98% confidence?

Count = 58    Mean = 98.896    Median = 98.400      MidRange = 98.600    StdDev = 0.8175           

Range = 2.800   IntQRange = 1.050

The answer is 362 (rounded to the nearest whole number)

How did they get this answer?  Please show me the steps.