To estimate the mean height of male students on your campus
     To estimate the mean height ? of male students on your campus, you will measure an SRS of students. You know from government data that the standard deviation of the heights of young men is about 2.9 inches. You want your sample mean  vector x to the value you found in the previous part?       vector x within one-half inch of ?? (Use the 68-95-99.7 rule)        How large an SRS do you need to reduce the standard deviation of vector x have so that 99.7% of all samples give an vector x to estimate ? with an error of no more than one-half inch in either direction.   What standard deviation (½0.0001) must  
  
  Solution
Here is what I solved before, please modify the figures as per your question. Please let me know if you have further questions. Ifthis helps then kindly rate 5-stars.
To estimate the mean height

