Reference no: EM132523229
An experiment was conducted in a supermarket to determine if a linear relationship exists between the amount of shelf-space allotted to a brand of soft-drink (say, brand A) and its weekly sales. The amount of shelf-space allotted to brand A was altered between 5, 6 and 9 ft2 in a random manner for a period of 6 weeks. The results of the experiments are as follows:
Shelf-Space allotted (x in ft2)
5 6 6 5 6 9
Weekly Sales (y in $) 337 520 467 502 630 517
Given: "" = 10.83, ** = 45129.5 "* = 216.5
[Do not use software to work out the answers for this question, i.e. do not get the regression line, confident/prediction interval etc., directly from software.]
a. Find the regression line using least squares method.
b. Find a 95% confidence interval for the slope coefficient of the regression line.
c. Find a 98% confidence interval for the expected weekly sales of brand A soft-drink if 7 ft2 of shelf-space is allotted.
d. Find a 90% prediction interval for the weekly sales of brand A soft-drink if 9 ft2 of shelf-space is allotted.