A study was made by a retail merchant to determine the relation between weekly advertising expenditures and sales. The following data were recorded: Advertising Costs ($) 40 20 25 20 30 50 40 20 50 40 Sales ($) 350 420 365 345 440 425 480 400 520 510 a) Plot a scatter diagram. b) Find the equation of the regression line to predict weekly sales from advertising expenditures. c) Estimate the weekly sales when advertising costs are $35. d) Evaluate s2 e) construct a 99% confidence interval for f) construct a 99% confidence interval for beta.