Using the data of Problem 15.6 on page 637, stored in Tomato, perform a square-root transformation of the independent variable (fertilizer application rate). Using yield as the dependent variable and the transformed independent variable, perform a regression analysis.
a. State the regression equation.
b. Predict the yield when 55 pounds of fertilizer is applied per 1,000 square feet.
c. Perform a residual analysis of the results and determine whether the regression model is valid.
d. At the 0.05 level of significance, is there a significant relationship between yield and the square root of the fertilizer application rate?
e. Interpret the meaning of the coefficient of determination, r2, in this problem.
f. Compute the adjusted r2.
g. Compare your results with those of Problems 15.6 and 15.12. Which model is best? Why?
h. How much fertilizer should you apply in order to grow the most tomatoes?