use SAS or minitab for this information

a, to predict the sale volume when x1 = 20000, x2 = 1.7, x3 = 500

b, to construct the 95% prediction interval for the sale volume when x1 = 20000, x2 = 1.7, x3 = 500

c, check whether the predictor x is needed by using a partial F test

TABLE 4.12 (for Exercise 4.11) Crest Toothpaste Sales Data U.S. Personal Disposable Income, X3 Year Crest Sales, y Ratio, X2 Crest Budget, X1 547.9 1967 105,000 16,300 1.25 1968 593.4 105,000 15,800 1.34 1969 121,600 16,000 1.22 638.9 1970 113,750 14,200 1.00 695.3 1971 113,750 15,000 1.15 751.8 1972 14,000 1.13 810.3 1973 128,925 142,500 126,000 15,400 1.05 914.5 1974 18,250 1.27 998.3 1975 162,000 17,300 1.07 1096.1 1976 191,625 23,000 1.17 1194.4 1977 189,000 19,300 1.07 1311.5 1978 210,000 23,056 1.54 1462.9 1979 224,250 26,000 1.59 1641.7 Source: C. I. Allmon, "Advertising and Sales Relationships for Toothpaste: Another Look," Business Economics (September 1982), pp. 17, 58. Reprinted by permission. Copyright 1982 National Association for Business Economics