Discuss the below:
Q: Product sales since 1984 are:
Year 1984 1985 1986 1987 1988 1989 1990 1991 1992
Sales 266 264 145 205 139 98 94 94 128
The least squares trend equation using the coded method is given:
Y1 = 159.22 - 21.18X, where X is set equal to 0 for 1984
a. What were the sales in 1988?
b. What will the sales be in 1993?
c. How much do the sales change per year from 1984 to 1992?
d. What's the 3 year moving average for 1984?