Question 9.173

67. Advanced Placement Californians. The College Board reports that the mean score on all advanced placement tests taken in California in 2012 was 2.95. Suppose that a random sample of 49 test scores for tests taken by Californians this year is 2.95. Assume the population standard deviation is 0.21.

523

  1. Construct a 95% confidence interval for the population mean test score for this year. (Hint: See Section 8.1.)
  2. Use the confidence interval to test, at level of significance , whether the population mean test score differs from the following amounts:
    1. 2.89
    2. 2.90
    3. 3.00
    4. 3.01

9.3.67

(a) (2.89, 3.01)

(b)

Value of
 Form of hypothesis test,
with 		Where lies
in relation to
95% confidence
interval		 Conclusion of
hypothesis test
(i) 2.89 Outside Reject
(ii) 2.90 Inside Do not reject
(iii) 3.00 Inside Do not reject
(iv) 3.01 Outside Reject