Since the emergence of Japan as an industrial superpower in the 1970s and 1980s, U.S. businesses have paid close attention to Japanese management styles and philosophies. Some of the credit for the high quality of Japanese products is attributed to the Japanese system of permanent employment for their workers. In the United States, high job turnover rates are common in many industries and are associated with high product defect rates. High turnover rates mean U.S. plants have more inexperienced workers who are unfamiliar with the company's product lines than Japan has. For example, in a study of the air conditioner industry in Japan and the United States, the difference in the average annual turnover rate of workers between U.S. plants and Japanese plants was reported as 3.1%. In a more recent study, five Japanese and five U.S. plants that manufacture air conditioners were randomly sampled; their turnover rates are shown below.
U.S. Plants Japanese Plants

7.11 3.52

6.06 2.02

8.00 4.91

6.87 3.22

4.77 1.92

Is there sufficient evidence to indicate that the mean annual percentage turnover for U.S. plants exceeds the corresponding mean percentage for Japanese plants? Test using α = .05. This is a t-test: Two-sample independent groups assuming equal variances.