Question 1:
In a study of distances travelled by buses before the first major engine failure, a sampling of 191 buses resulted in a mean of 154,700 km and a standard deviation of 60,000 km. At the 0.05 level of significance, test the manufacturer's claim that mean distance travelled before a major engine failure is more than 144,000 km. Use the 4 steps outlined in the examples in Module 13 to answer this question.
Question 2:
A night time cold medicine bears a label indicating the presence of 600 mg of acetaminophen in each fluid ounce of the drug. Suppose that Health Canada randomly selected 65 one-ounce samples and found that the mean acetaminophen content was 589 mg and the standard deviation was 21 mg. Using α = 0.02, test the claim of the pharmaceutical company that the population mean is different from 600 mg. Would you by this cold medicine? Give your reasons.
Question 3:
Use a significance level of α = 0.02 to test the claim that µ ≠ 64.8. The sample data consist of 12 scores for which the = 59.8 and s = 8.7.
Question 4:
The expense of moving the storage yard for the Consolidated Package Delivery Service (CPDS) is justified only if it can be shown that the daily mean travel distance will be less than 342 km. In trial runs of 12 delivery trucks, the mean and standard deviation are found to be 318 km and 67 km, respectively. At the 0.01 level of significance, test the claim that the mean is less than 342 km. Should the storage yard be moved? Give your reasons.