Q5.10 Managers often study the profit margin-sales relation over the life cycle of individual products, rather than the more direct profit-sales relation. In addition to the economic reasons for doing so, are there statistical advantages as well? (Note: Profit margin equals profit divided by sales.)

A. Describe the economic meaning and statistical significance of each individual independent variable included in the Mrs. Smyth's frozen fruit pie demand equation.
B. Interpret the coefficient of determination (R2 )
for the Mrs. Smyth's frozen fruit pie demand equation.
C. Use the regression model and 2007-4 data to estimate 2008-1 unit sales in the WashingtonArlington-Alexandria market.
To illustrate use of the standard error of the estimate statistic, derive the 95 per cent and 99 per cent confidence intervals for 2008-
1 unit sales in the Washington-ArlingtonAlexandria market.