The annual demand for new automobile in the United States from 1971 to 1986 are shown below:
From the data
1 Find the sale forecasting equation of the form Y=a+b12X1+b2X2+b2X3 and graph it
2 Discuss the goodness of fit between the actual and the estimated sale of new cars first using developsed in (1) above and second using the value of the RSQ.
3 Discuss the specific meanings of the regression coeffients, b1X1, b2X2 and b3X3.
4 Assume that in 1990, the consumer price index will be 400, monthly per capita personal income $4,000 and the interst rate 7 %. Estimate the sale of new cars for 1990.
| Years |
Cons. Pr. Inc in dollars |
Monthly Per. Ionc in dollars |
Int Rate in percent |
New Cars Sold |
|
X1 |
X2 |
X3 |
Y |
| 1971 |
121.3 |
776.8 |
4.89 |
10227 |
| 1972 |
125.3 |
839.6 |
4.55 |
10872 |
| 1973 |
133.1 |
949.8 |
7.38 |
11350 |
| 1974 |
147.7 |
1038.4 |
8.61 |
8775 |
| 1975 |
161.2 |
1142.8 |
6.16 |
8539 |
| 1976 |
170.5 |
1252.6 |
5.22 |
9994 |
| 1977 |
181.5 |
1379.3 |
5.5 |
11046 |
| 1978 |
195.4 |
1151.2 |
7.78 |
11164 |
| 1979 |
217.4 |
1729.3 |
10.25 |
10559 |
| 1980 |
246.8 |
1918 |
11.28 |
8979 |
| 1981 |
272.4 |
2127.6 |
13.73 |
8535 |
| 1982 |
289.1 |
2261.4 |
11.2 |
7980 |
| 1983 |
298.4 |
2428.1 |
8.69 |
9179 |
| 1984 |
311.1 |
2670.6 |
9.65 |
10394 |
| 1985 |
322.2 |
2841.1 |
7.75 |
11039 |
| 1986 |
328.4 |
3022.1 |
6.31 |
11450 |
| 1990 |
400 |
4000 |
7% |
? |