# Choosing Distributions You plan to construct a confidence interval for the population mean μ. Use…

Choosing Distributions You plan to construct a confidence interval for the population mean μ. Use the given data to determine whether the margin of error E should be calculated using a critical value of (from the normal distribution), a critical value of (from a t distribution), or neither (so that the methods of Section 7-3 and this section cannot be used).a. n = 9, = 75, s = 15, and the population has a normal distribution.b. n = 5, = 20, s = 2, and the population has a very skewed distribution.c. n = 12, = 98.6, ?? =0.6 and the population has a normal distribution. (In reality, is ?? rarely known.)d. n = 75, = 98.6, ?? =0.6 and the population has a skewed distribution. (In reality, is rarely known.)e. n = 12, = 98.6, s =0.6 and the population has a skewed distribution.