A survey is conducted to determine whether the age of car influences the annual maintenance cost. A sample of 10 cars is selected and the data is shown below.

Age of Car (months) x	Annual Maintenance Costs ($) y
3	120
5	115
6	135
7	290
9	275
10	300
11	350
13	475
14	500
15	550

a. Test whether each of the regression parameters ${\beta }_0$ and ${\beta }_1$ is equal to zero at a 0.05 level of significance.

b. Interpret the estimated regression parameters. Are these interpretations reasonable?