7. Information supplied by a mail-order business for 12 cities is shown in Table P-7.
a. Determine the fitted regression line.
b. Calculate the standard error of the estimate.
c. Determine the ANOVA table.
d. What percentage of the variation in mail orders is explained by the number of
e. Test to determine whether the regression slope coefficient is significantly differ
ent from zero. (Use the .01 significance level.)
f. Test for the significance of the regression using the
statistic from the ANOVA
table. (Use the .01 significance level.) Is the result consistent with the result in
part e? Should it be?
g. Forecast the number of mail orders received when 10,000 catalogs are distrib
uted with a 90% prediction interval.