# The proportion of parts in an inventory that are outdated and no

1)      The proportion of parts in an inventory that are outdated and no longer useful is thought to be 0.10. To check this, a random sample of n = 100 parts is selected and 14 are found to be outdated. Based upon this information, what is the probability of 14 or more outdated parts?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.