8. (12 pts) (3 pts each) State whether you would use the z-distribution, t-distribution, x-distribution, or none of these to calculate critical values in each of the scenarios. Show any work needed to decide. (a) Confidence interval for the percentage of households with landline telephones, n = 12, p=0.3 (b) Test the claim: The mean weight of women who won Miss America titles is equal to 121 lb, population normal, n=20,s - 5.2 (c) Confidence interval for standard deviation of IQ scores of statistics teachers, population is skewed, 18 stats teachers are sampled, S = 5.2