I need to find the margin of error for each

1) Suppose you know the population is normally distributed and that the population standard deviation is 7.5.

Calculate the margin of error for a confidence interval of 95% for a sample size of 12.

2) Suppose you know the population is normally distributed and that the population standard deviation is 7.28.

Calculate the margin of error for a confidence interval of 85% for a sample size of (Round your answer to three decimal places.)

3) Suppose you know the population is normally distributed and that the population standard deviation is 7.5.

Calculate the margin of error for a confidence interval of 90% for a sample size of (Round your answer to three decimal places.)