A real estate builder wishes to determine how house size (House) is influenced by family income (Income X1), family size (Size X2), and education of the head of household (School X3). House size is measured in hundreds of square feet, income is measured in thousands of dollars, and education is in years. The builder randomly selected 50 families and ran the multiple regression. The estimated coefficients are

Coefficients: 

Estimate (Intercept) -1.6335 X1 0.4485 X2 4.2615 X3 -0.6517

Std. Error 5.8078 0.1137 0.8062 0.4319

(a) What would be the predicted house size (in hundreds of square feet) for an individual earning an annual income of $50,000, having a family size of 3, and going to school a total of 15 years? Show computation.

(b) Test if2, the coefficient for variable X2, is significantly different from 5. Use= 0.05.