1) The proportion of parts in an inventory that are outdated and no longer useful is thought to be 0.10. To check this, a random sample of n = 100 parts is selected and 14 are found to be outdated. Based upon this information, what is the probability of 14 or more outdated parts?
2) From a sample of 90 people, 30% disagreed with a statement.
a) Construct a 95% confidence interval for the proportion of people agreeing with the statement.
b) Construct a 95% confidence interval for the proportion of people disagreeing with the statement.
c) Compare the lengths of the confidence intervals in parts a) and b).
3) A random sample of size 20 revealed 12 respondents in favor of a proposal. Test the hypothesis that the proportion in favor differs from .52 using a 5% significance level.
4) Construct a 90% confidence interval for the difference of two population proportions using x1 = 38, n1 = 50, and x2 = 45, n2 = 50.