During the last decade, a number of institutions dedicated to improving the quality of products ...

     During the   last decade, a number of institutions dedicated to improving the quality of   products and services in the United States have been formed.  Many   of these groups annually give awards to companies that produce high quality   goods and services.  An investor believes that publicly traded   companies that win awards are likely to outperform companies that do not win   such awards.  To help determine his return on investment in such   companies, he took a random sample of 83 firms that won quality awards the   previous year and computed the annual return he would receive had he   invested.  Is there sufficient evidence, at the 1 percent   significance level to suggest that the average return of these stocks exceeds   the market average return for high growth stocks for that   year?  Assume that the market average return for high growth stocks   is 12.7 percent.    

     x   16.2   15.34   19.55   13.53   6.76   13.9   11.72   17.63   10.97   22.1   0.58   16.65   24.6   -2.27   -0.67   12.8   26.01   15.46   -1.16   7.41   25.47   27.25   25.46   18.07   2.62   13.45   9.45   12.74   13.6   -3.6   11.42   28.26   21.45   21.36   23.8   9.01   26.58   6.51   18.63   24.69   16.34   22.69   -0.21   7.76   2.28   6.89   23.94   9.62   13.72   21.39   -1.06   22.45   7.23   26.2   21.93   21.02   17.85   7.9   12.54   20.95   15.52   16.82   17.52   29.68   18.02   22.37   25.32   22.78   14.65   21.15   5.14   14.3   24.77   23.33   9.88   18.41   2.26   16.52   5.66   6.39   15.45   21.58   14.15