15) An economist in a large city wanted to develop a model to estimate the vacancy rate of downtown office space (the percent of available office space that was unoccupied) based on the monthly rental price per square foot. She took a random sample of various office buildings in the downtown area and created three
models using monthly rental prices (x) to predict vacancy rate (y).

-A model using (x, y) produced a regression equation of ŷ = -3.019 + 1.176x and the residual plot showed strong curvature.

-A model using (x,√√) produced a regression equation of √y = 1.3497 +0.157x and the residual plot indicated that the variance increased as the rental prices increased (a "fanning" effect).

-A model using (x, log y) produced a regression equation of log y = 0.538 +0.038x and the residual plot showed no apparent pattern.

Based on the above information, which would be the most reasonable prediction of vacancy rate if the monthly
rental price were $12.00 per square foot?
(A) 3.23%
(B) 9.86%
(C) 10.46%
(D) 11.09%
(E) 12%