Conduct individual hypothesis tests to determine if any of the independent variables can be dropped ...

       Fran’s Convenience Marts are located throughout metropolitan   Erie, Pennsylvania. Fran, the owner, would like to expand into other   communities in northwestern Pennsylvania and southwestern New York, such as   Jamestown, Corry, Meadville, and Warren. To prepare her presentation to the   local bank, she would like to better understand the factors that make a   particular outlet profitable. She must do all the work herself, so she will   not be able to study all her outlets. She selects a random sample of 15 marts   and records the average daily sales (Y), the floor space (area), the number   of parking spaces, and the median income of families in that ZIP code region   for each. The sample information is reported below.          Sampled   Daily Store Parking Income    Mart Sales (y) Area (x1) Spaces (x2) Income ($ thousands) (x3)   1 1,840 532 6 44   2 1,746 478 4 51   3 1,812 530 7 45   4 1,806 508 7 46   5 1,792 514 5 44   6 1,825 556 6 46   7 1,811 541 4 49   8 1,803 513 6 52   9 1,830 532 5 46   10 1,827 537 5 46   11 1,764 499 3 48   12 1,825 510 8 47   13 1,763 490 4 48   14 1,846 516 8 45   15 1,815 482 7 43          a. Determine   the regression equation.    b. What is   the value of R2? Comment on the value.   c. Conduct a   global hypothesis test to determine if any of the independent variables are   different   from zero.      d. Conduct   individual hypothesis tests to determine if any of the independent variables   can be   dropped.