NOTE: Use 4 decimals for all your calculations and answers. If it's not possible, use 3 or 2 decimals depending on the situation, but for the vast majority of calculations and answers, 4 decimals will be the norm.

The sales manager of various branches of a sports equipment store has launched a national advertising campaign for a few months. The monthly costs (in thousands of dollars) for advertising over a 10-month period and the corresponding net revenue (in thousands of dollars) before tax are presented in the table below.

Month	Net Revenue Before Tax (y) $000	Monthly Ad Cost (x) $000
January	135	11
February	212	18
March	180	12.2
April	212	19.8
May	200	17.5
June	162	15.2
July	150	14.2
August	172	16.5
September	155	13
October	180	15

Based on the distribution of the points, one can assume that there is a linear relationship between these two variables.

a) Identify i) the dependent variable; ii) the independent variable. b) Determine the coefficients of the regression line given that NOTE: You must use a different formula than the one in d) for b1. n = 10 ?xy = 27340 x? = 15.2400 y? = 175.8000 sx = 7.6093 sy = 689.9556 c) Calculate the correlation coefficient between the two variables using the expression r = (?xiyi - n x? y?) / ((n - 1)sx sy) d) Verify the slope calculation of the regression line using the expression b1 = r (sy / sx) e) The manager wants to spend $17,000 on advertising in November. What net revenue can she expect if she uses the regression equation as a prediction tool? f) The assistant manager suggests a big push and spending $24,000 on advertising. Do you think the suggestion is "reasonable"? Explain.

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