A horticulturist is studying the relationship between tomato plant height and fertilizer amount. Thirty tomato plants grown in similar conditions were subjected to various amounts of fertilizer over a four-month period, and then their heights were measured. A portion of the results is shown in the accompanying table.

Fertilizer AmountTomato Plant Height

(ounces)............................................(inches)

1.9..........................................................20.4

5.0..........................................................29.1

⋮...................................................................⋮

3.1..........................................................36.4

a. Estimate the linear regression model: Height = β0 + β1 Fertilizer + ε.

b. Estimate the quadratic regression model: Height = β0 + β1Fertilizer + β2 Fertilizer2 + ε.

Find the fertilizer amount at which the height reaches a minimum or maximum.

c. Use the best-fitting model to predict, after a four-month period, the height of a tomato plant that received 3.0 ounces of fertilizer.