There appears to be some evidence suggesting that earlier retirement may lead to memory decline (Rohwedder & Willis, XXXXXXXXXXThe researchers gave a memory test to men and women aged 60–64 in several...

There appears to be some evidence suggesting that earlier retirement may lead to memory decline

(Rohwedder & Willis, 2010). The researchers gave a memory test to men and women aged 60–64 in

several countries that have different retirement ages. For each country, the researchers recorded the average memory score and the percentage of individuals in the 60–64 age range who were retired. Note that a higher percentage retired indicates a younger retirement age for that country. The following data are similar to the results from the study.

• 
  Identify the two hypotheses. Determine the critical region for your decision (use
  α
  = 0.05) and Compute the test statistic.
  

• Use the test statistic to make a decision and interpret that decision.