Here are plots of two regression analyses of roller coaster Speed against Height. The first is for roller coasters that don’t have inversions and the second is for roller coasters that do.

a) Would a single indicator variable for Inversions added to the regression equation enable us to obtain one regression equation for both sets of data? Explain.

b) Choose an appropriate set of explanatory variables, using an indicator variable (Inv = 1 for no inversions and 0 for some inversions) as necessary, and perform the regression analysis for the combined data set. Write the regression equation. Interpret the meaning of each coefficient and indicate whether the coefficient is significant at the 90% level.

Transcribed Image Text:

80 70 60 50 40 30 20 10 20 40 60 80 100 Height 80 70 60 + 50 40 30 20 10 20 40 60 80 100 120 140 Height + + + + peads peads