The Wall Street Journal's Shareholder Scoreboard tracks performance of 1000 major U.S. companies (The Wall Street Journal, March 10, 2003). The performance of each company is rated based upon the annual total return, comprising stock price changes and the reinvestment of dividends. Ratings are assigned through dividing all 1000 companies in five groups from A (top 20%), B (next 20%), to E (bottom 20%). Shown here are one-year ratings for sample of 60 of the largest companies. Do the largest companies differ in performance from performance of 1000 companies in the Shareholder Scoreboard? Use? = .05.
A=5, B=8, C=15, D=20, E=12
1. Compute the test statistic?
2. Determine the p-value?