Hi Can You Please Help Me With The Following Equation And Explain How To Get The

Hi Can you please help me with the following equation and explain how to get the result?

For a population data set, σ=12.5

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  1. How large a sample should be selected so that the margin of error of estimate for a 99% confidence interval for μ is 2.50?
  2. How large a sample should be selected so that the margin of error of estimate for a 96% confidence interval for μ is 3.20?