For Exercises 19–22, do the following:

  1. Check the normality conditions.
  2. State the hypotheses and the rejection rule for the -value method, using level of significance .
  3. Find .
  4. Find the -value.
  5. Compare the -value with level of significance . State the conclusion and the interpretation.

Question 9.285

19. Test whether the population proportion exceeds 0.4. A random sample of size 100 yields 44 successes.

9.5.19

(a) We have and , so we can use the test for proportions. (b) . Reject if the (c) 0.82 (d) (e) Since the is not , we do not reject . There is insufficient evidence that the population proportion is greater than 0.4.