Over the last five years in Pa. The variance of new home construction costs has been $108,000. Over the same period of time, based on a sample of 60 new homes , the variance of construction costs in Chester County has been $117,000. Can we conclude at an alpha level of .05 that there is greater variance in new construction cost in Chester County? The accounting department analyzes the variance of the weekly unit cost reported by two production departments. A sample of 16 cost reports for each of the two departments shows cost variances of 2.3 and 5.4, respectively. Is this sample information sufficient to conclude that the two production departments differ in terms of unit cost variance? Use alpha = .10. The Wall Street Journal Corporate Perceptions Study 2011 surveyed breeders and asked now each rated the quality of management and the reputation of the company for over 250 world-wide corporations. Both the quality of management and the reputation of the company were rated on an excellent, good, and fair categorical scale. Assume the sample data for 200 respondents below applies to this study. Reputation of Company Quality of Management. Excellent. Good. Fair Excellent 40. 25. 5 Good 35. 35. 10 Fair. 25. 10. 15 Use a .05 level of significant and test for independence of the quality of management and the reputation of the company. The Wall Street Journal's Shareholder Scoreboard tracks the performance of 1000 major U.S. companies. The performance of each company is rated based on the annual total return, including stock price changes and the reinvestment of dividends. Ratings are assigned by dividing all 1000 companies into five groups from A(top 20%), B (next 20%), to E (bottom 20%). Shown here are the one-year ratings for a sample of 60 of the largest companies. Do the largest companies differ in performance from the performance of the 1000 companies nine the Shareholder Scoreboard? Use alpha = .05 A random sample of final exam grades for a college course follows. 55. 85. 72. 99. 48. 72. 88. 67. 98. 80. 74. 93. 85. 78. 86 82. 90. 71. 83. 60. 95. 77. 84. 70. 63. 95. 79. 51. 84. 91 76. 81. 78. 65. 75. 86. 70. 80. 64 84 Using alpha = .05 and test to determine whether a normal probability distribution should be rejected as being represented of the population of grades. The sample mean is 77.85 and the standard deviation is 12.32