You wish to learn the average age of an MBA student within 2 years and with 99% confidence. How large of a sample should you get?

Based on data from student_data.xls

This is what I have so far. I don't know what the standard deviation would be

N= [ZS/E]^2

N= [ 2.5758*s/2] ^ 2

To determine the sample size required to estimate the average age of MBA students with a 99% confidence level and a margin of error within 2 years, we need to know the standard deviation of the age of MBA students.

Since you mentioned that you have data from student_data.xls, you can calculate the standard deviation using the following steps:

1. Open the student_data.xls file and locate the column containing the age of MBA students.
2. Calculate the standard deviation for this age column using a statistical software tool like Microsoft Excel or by using statistical functions like STDEV.P or STDEV.S.
3. Once you have the standard deviation value, you can substitute it into the formula you provided to calculate the sample size.

The formula you have is:

N = [Z * S / E]^2

Where:
N = Sample size
Z = Z-score corresponding to the desired confidence level (99% confidence level corresponds to a Z-score of approximately 2.5758)
S = Standard deviation
E = Margin of error (in this case, 2 years)

By substituting the values into the formula, you can calculate the sample size needed to estimate the average age of MBA students.