Consider a population with a known standard deviation of 26.8. In order to compute an interval estimate for the population mean, a sample of 64 observations is drawn.

a. Is the condition that is normally distributed satisfied? Explain.

b. Compute the margin of error at a 95% confidence level.

c. Compute the margin of error at a 95% confidence level based on a larger sample of 225 observations.

d. Which of the two margins of error will lead to a wider confidence interval?

The margin of error with 6.3% confidence.

The margin of error with 99% confidence.