2. On the basis of the following data, the marketing manager wants to predict the sales

volume for the locality on the basis of # households, number of cars and marketing

expense

Sl.No. Sales Volume #Households number of cars marketing expense

1 15727 161 3 180

2 9328 99 1 150

3 13681 135 2 175

4 12379 120 2 165

5 15351 164 3 178

6 24174 221 5 220

7 20154 179 4 205

8 20671 204 5 210

9 22978 214 5 128

10 13522 101 1 176

11 22471 231 5 226

12 19529 206 4 296

13 24216 248 3 240

14 11521 107 2 168

15 197.82 205 3 100

i. Draw three scatter plots of sales volume with each of the three variables and comment

on their correlation.

ii. Regress the sales volume on #household, number of cars and marketing expense.

Calculate R square and interpret the same.

iii. Determine which variable is/are significant variable/s. Is there any insignificant

variable? If yes, regress again, by dropping the variable. Will dropping that variable

increases the adjusted R square?