Business Focus B2C B2B Total A survey of B2B marketers (marketers that focus primarily on attracting businesses) and B2C marketers (marketers that primarily target consumers) was based on 1000 B2B….
The data in the next were obtained in a forestry study of certain characteristics of a stand of pine trees including A, age of a particular pine stand
The data in the next were obtained in a forestry study of certain characteristics of a stand of pine trees including A, age of a particular pine stand; HD, the average height of dominant trees in feet; N, the number of pine trees per acre at age A; and MDBH, the average diameter measured at breast height (4.5 feet above ground). A theoretical analysis suggested that the following model is appropriate: Model (Y = MDBH|X1 = HD, X2 = A × N, X3 = HD/N). (a) Fit this model to the data. Compute R2 and R2 a (the adjusted R-squar. (b) Test the hypothesis H0 : β3 = 0 against H1 : β3 = 0. State your conclusions. (c) Fit the reduced Model (Y = MDBH|X1 = HD, X2 = A × N). Compute R2 and R2 a for the reduced model. (d) For each model prepare a of fitted values, standard error of prediction, etc., similar in format to that. Compare the full and reduced models by comparing the standard errors of prediction. Which model performs better?
(Source: R.H. Myers (1990), Classical and Modern Regression with Applications, 2nd ed., PWS-Kent, Boston. Used with permission.)