b How does the confidence interval change as the confidence

b. How does the confidence interval change as the confidence level changes?

c. How does the confidence interval change as the sample size changes?

d. How does the confidence interval change as the population standard deviation changes?

e. How does the width of your confidence interval affect the precision of your estimation of the population mean ??

2, when the population from which we sample is normally distributed with an unknown mean and a known population standard deviation , the formula of a 95 % confidence interval for the population m ean is given by X 20.975-, X + 20.975 Vn The termi 20975 on is called the rnargin of error (ME), where X, , and n are the sample mean, population standard deviation and sample size, respectively. 20.975 is the critical value of a standard normal distribution, which depends on the confidence level. The margin of error changes as o, n and z0.975 change. Answer the questions below. (a) (5) Derive the formula of a 95 % confidence interval for the population mean , which is shown above.

Solution