The manager of a bookstore wants to predict Sales from Number of Sales People Working using the accompanying data.

Number of sales people working 2 3 8 10 12 12 14 15 18 19

Sales (in $1000) 10 11 14 17 19 20 20 23 23 25

x = 11.3 y = 18.2

SD(x) = 5.72 SD(y) = 5.14

r = 0.985

a) Find the slope estimate, b1

b1 = ??? (round to three decimal places as needed)