You are the general manager of a car-rental service at the airport. In an effort to estimate the maintenance costs you obtain the following data from a random sample of 11 cars.
X = number of miles the car has been driven (in thousands) and Y = total maintenance cost in dollars.
X 3 5 12 8 3 16 12 9 2 4 10
Y 90 150 320 208 98 390 275 240 75 115 265
a. Calculate the sample correlation coefficient.
b. Use the 1% significance level to test for a positive population correlation between the number of miles driven and maintenance cost.