Wk8

Problem 51

Refer to the Lincolnville School District bus data.

a. Conduct a test of hypothesis to reveal whether the mean maintenance cost is equal for each of the bus manufactures. Use the .01 significance level.

b. Conduct a test of hypothesis to determine whether the mean miles traveled since the last maintenance is equal for each bus manufacturer. Use the .05 significance level.

Problem 57

A survey investigated the public's attitude toward the federal deficit. Each sampled citizen was classified as to whether he or she felt the government should reduce the deficit or increase the deficit, or if the individual had no opinion. The sample results of the study by gender are reported below.

Gender        Reduce the Deficit           Increase the deficit         No Opinion

Female           244                             194                                         68

Male               305                             114                                         25

At the .05 significance level, is it reasonable to conclude that gender is independent of a person's position on the deficit?

Problem 64

Refer to the Lincolnwood School District bus data.

a. Suppose we consider a bus “old” if it has been in service more than 8 years. At the

.01 significance level, can we conclude that less than 40% of the district’s buses are

old? Report the p-value.

b. Find the median maintenance cost and the median age of the buses. Organize the

data into a two-by-two contingency table, with buses above and below the median of

each variable. Determine whether the age of the bus is related to the amount of the

maintenance cost. Use the .05 significance level.

c. Is there a relationship between the maintenance cost and the manufacturer of the

bus? Use the breakdown in part (b) for the buses above and below the median maintenance cost and the bus manufacturers to create a contingency table. Use the .05

significance level.