For Exercises 7–10, perform the indicated Welch's hypothesis test using the -value method. The summary statistics were taken from random samples that were drawn independently. For each exercise follow these steps:

  1. State the hypotheses and the rejection rule.
  2. Calculate .
  3. Find the -value.
  4. Compare the -value with level of significance . State and interpret your conclusion.

Question 10.60

9. Test, at level of significance , whether .

Sample 1
Sample 2

10.2.9

(a) . Reject if the ≤ 0.05.

(b) . (c) . (d) Since the is ≤ 0.05, we reject . There is evidence at the level of significance that the population mean of Population 1 is less than the population mean of Population 2.