Page 233 - BA2 Integrated Workbook - Student 2017
P. 233
Supplementary objective test questions
The following information relates to questions 3.2 and 3.3:
LMN run a chain of restaurants. It is trying to establish if there is a relationship
between expenditure on local newspaper advertising and the sales revenue of the
restaurants. The annual data for a random sample of ten restaurants are as follows:
Restaurant code Advertising Spend (x) Sales (y)
($000)
($000)
111 1.0 55
124 1.5 55
254 1.0 45
345 2.0 50
413 2.0 65
433 2.5 60
576 2.5 55
790 3.0 70
873 3.5 65
908 4.0 80
The following additional data is given:
∑xy = 1457.5
2
∑x = 62
2
∑y = 36,950
3.2 Calculate the regression coefficient (b) for the regression line of sales on
advertising spend. (to 3 decimal places)
3.3 Calculate the correlation coefficient (r) between sales and advertising
spend. (to 2 decimal places)
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