Question

According to a magazine, the number of stores that a coffee chain operates worldwide between 1999 and 2003 is as follows where x = 0 corresponds to 1999.
Year, x 0 1 2 3 4
Stores, y 2170 3629 4405 5757 7068
(a) Find an equation of the least-squares line for these data
which is y=1192.4x+2221

(b) Use the result of part (a) to estimate the rate at which new stores were opened annually for the period in question.