3.74. In a study of graduate students who took the Grad-\n uate Record Exam (GRE), the Educational Testing Ser-\n vice recently reported that for the quantitative exam, U.S.\n citizens had a mean of 529 and standard deviation of 127,\n whereas the non-U.S. citizens had a mean of 649 and stan-\n dard deviation of 129.\n(a) Scores on a difficult exam have a mean of 57 and a\n standard deviation of 20. The teacher boosts all the scores\n by 20 points before awarding grades. Report the mean and\n standard deviation of the boosted scores.\n(b) Suppose that annual income of Canadian lawyers has\n a mean of $100,000 and a standard deviation of $30,000.\n Values are converted to British pounds for presentation to\n a British audience. If one British pound equals $2.00, re-\n port the mean and standard deviation in British currency.\n(c) Observations from a survey that asks about the num-\n ber of miles traveled each day on mass transit are to be\n converted to kilometer units (1 mile = 1.6 kilometers).\n Explain how to find the mean and standard deviation of\n the converted observations.