Refer to Problem 20. Consider only the variables chicken consumption, income, and chicken price in the original units. Compute simple differences for each of the variables. Using the differenced data, regress the change in chicken consumption on the change in income and the change in chicken price. Examine the residuals. Interpret the results of your regression analysis. Do either of the predictor variables have much explanatory power? Explain.
Problem 20
The demand for a commodity typically depends on the income of the consumer, the real price of the commodity, and the real price of complementary or competing products. Table P-20 gives the per capita consumption of chicken in the United States (in pounds); the per capita disposable income (in dollars); and the retail prices for chicken, pork, and beef (in cents per pound) for several years.

2224249571801696253666 54 55 54 63 69 65 64 70 73 67 42 38 40 39 37 38 39 37 38 40 38 39 39 52 48 58 532 .7 9 6 3 6 48 61596451217 9959 9 3 2 797018 28, 29, 30, 30, 31 33 35 35 37 38 -1234567891123456789 20 21 22 23