Question 7 (a) Explain what bivariate means. (1) (b) Using the data in the frequency table below compute the correlation coefficient between advertising expenditure and sales. The data represent the number of months in which advertising expenditure was in a particular class AND sales were in a certain range. (17) (c) Interpret the result, explaining what the coefficient of determination means and how it can be used. (2) [20] Sales (R'000s) 10-19 20-29 30-39 40-49 50-59 100-199 12 3 0 2 0 Ad. expend. 200-299 0 8 3 4 0 (R'00s) 300-399 3 5 14 2 3 400-499 0 8 8 20 5 500-599 0 2 12 13 28