First name:   Last name:

According to the U.S. EPA, the average real-world fuel economy of new cars in the sedan/hatchback category for five model years is given by the following table:

Let x represent time in years since 2015 and let y represent the average fuel economy for sedans/hatchbacks in miles/gallon.

1.  According to the above table, find y when x = 3.

a.  29.0

b.  30.2

c.  30.8

d.  30.9

d.  32.0

2.  Compute the correlation coefficient r.

a.  -.855

b.  .855

c.  .920

b.  .966

c.  1

3.  What percentage of the response variable y can be explained by the variable x?

a.  85.5\(\%\)

b.  93.4\(\%\)

c.  96.6\(\%\)

d.  98.1\(\%\)

d.  100\(\%\)

4.  Find the regression line (remember in 2015, x = 0).

a.  \(\hat{y} = 29.24 + .67 x\)

b.  \(\hat{y} = 29.04 + .67 x\)

c.  \(\hat{y} = 29.24 + .71 x\)

d.  \(\hat{y} = 29.04 + .71 x\)

5.  Use your line to predict the average fuel economy in 2022.

a.  33.7 miles/gallon

b.  33.9 miles/gallon

c.  34.0 miles/gallon

d.  34.1 miles/gallon

d.  34.2 miles/gallon