City government has collected the following data on annual sales tax collections and new car registrations for the past 5 years:

4.      City government has collected the following data on annual sales tax collections and new car registrations for the past 5 years:

Year                                                     1        2          3         4        5

Annual Sales Tax Collection               1.9     2.0      2.8     2.1    3.3

(in millions)

New Car Registrations                        10       12       14       16     18

a)      Determine The Least -squares regression equation. 

a)      In the context of this problem, interpret a and b.