chapter work statistics

Submit output in one Excel file.

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 manufacturers. 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.

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.