For Exercises 23–25, do the following:

  1. Check the normality conditions.
  2. State the hypotheses.
  3. Find and the rejection rule.
  4. Calculate .
  5. State the conclusion and the interpretation.

Question 9.408

23. Test whether the population proportion exceeds 0.8. A random sample of size 1000 yields 830 successes. Let .

9.99.23

(a) We have and . (b) (c) . Reject if . (d) (e) Since , we reject . There is evidence that the population proportion is greater than 0.8.