Mathematical Process Standards>Analyzing Mathematical Relationships to Connect Ideas(TEKS.AQR.9-12.1.F) Practice Test

A linear model is used to predict a Texas county's corn yield (bushels per acre) from annual rainfall. For County A, the model predicted 120 bushels per acre, and the actual yield was 105.

A student collected monthly kWh and bill amounts from 4 apartments in one Texas building and fit $\hat{y} = 0.09x + 25$ with $r = 0.99$. The student concludes: "Across Texas, electricity costs 9 cents per kWh and bills can be predicted almost perfectly by this line."