Question

Ten sales regions of equal sales potential for a company were randomly selected. The advertising expenditures (in units of $10,000) in these 10 sales regions were purposely set during July of last year at, respectively, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14. The sales volumes (in units of $10,000) were then recorded for the 10 sales regions and found to be, respectively, 107, 130, 129, 123, 117, 97, 116, 130, 113, and 118. Assuming that the simple linear regression model is appropriate, it can be shown that b₀ = 121.2242, b₁ = -.3394.

Find a 95 percent confidence interval for the slope β₁ of the simple linear regression model describing the sales volume data. (Do not round intermediate calculations. Negative amounts should be indicated by a minus sign. Round your answers to 3 decimal places.)

  The 95 percent confidence interval for β₁ = [, ]

Answer 1

The statistical software output for this problem is:

From above output, 95% confidence interval will be:

[-3.201, 2.522]