Consider the following time series data and the regression analysis given below:
| Year(t) |
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Average Temperature |
Sales(YT) |
| 1 |
8 |
80 |
6 |
| 2 |
6 |
84 |
11 |
| 3 |
4 |
90 |
9 |
| 4 |
7 |
81 |
14 |
| 5 |
10 |
77 |
15 |
| 6 |
11 |
81 |
|
a) Construct the regression equation?
b) Forecast year 6?
c) Data analyst noticed that he fat fingered sales data for year 5 incorrectly, it should be 12 instead of 15. Do the data analysis again and construct the new regression equation and advise which model can potentially produce better results? Make your comparison and explain why?