Question 9.383

32. Credit Scores in Georgia. According to CreditReport.com, the mean credit score in Georgia in 2014 was 668. Suppose we have a recent random sample of 900 credit scores in Georgia, and assume that the population standard deviation is 150. We are interested in testing using level of significance whether the population mean credit score in Georgia has decreased since that time.

  1. Describe what a Type II error would mean in the context of this problem.
  2. What is the probability of making a Type II error when the actual mean credit score takes the following values?
    1. 650
    2. 645
    3. 640
    4. 635
  3. Calculate the power of the hypothesis test for the values of given in (b).
  4. Construct the power curve for the values of given in (b).