Note: Attempt all questions as per rubric. Problems has a weightage of 10 marks each. The maximum you can score is 50. Use Excel function wherever possible. Unless otherwise noted, use = 0.05.

The following data represent a company's yearly sales volume and its advertising expenditure over a period of 8 years.

Year	Sales in Millions of Dollars (Y)	Advertising in ($10,000) (X)
1994	15	32
1995	16	33
1996	18	35
1997	17	34
1998	16	36
1999	19	37
2000	19	39
2001	24	42

a) Develop a scatter diagram of sales versus advertising.

b) Use the method of least squares to compute an estimated regression line between sales and advertising.