1. In the iris data, build a linear regression model to predictSepal.Length based on both Petal.Length and Species.
a. Calculate the regression equation, including theinteraction.
b. From this equation, you should be able to find 3 regressionlines (one for each Species). Interpret each of the 3 slopes of thelines in the context of the problem. Remember that both numericalvariables are measured in centimeters.
c. Plot the 3 regression lines in a scatterplot of Sepal.Lengthvs. Petal.Length. Use a different color for each Species.
d. Predict the Sepal.Length for a Versicolor iris with a petalthat is 3.4 cm long.
e. Conduct a partial ?-test to see if the Petal.Length:Speciesinteraction terms are significant. State the hypothesis, ?-value,and conclusion of the test.
f. Now calculate the regression equation without the interactionterm. Interpret the slope in the context of the problem.
g. Using the no-interaction model, I’m 90% sure that the sepallength of a Virginica iris with a 5.5-cm-long petal will be between__________ cm and __________ cm.
h. Identify and interpret the ? 2 from the no-interactionmodel.
