Find and interpret a 95 percent confidence interval for the slope 1 of the simple linear regression

Question:

Find and interpret a 95 percent confidence interval for the slope β1 of the simple linear regression model describing the sales volume data in Exercise.
In exercise
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:
89, 87, 98, 110, 103, 114, 116, 110, 126, and 130
Assuming that the simple linear regression model is appropriate, it can be shown that b0 = 66.2121, b1 = 4.4303, and SSE = 222.8242. Calculate s2 and s.