Firms planning to build new plants or make additions to existing facilities have become very conscious of the energy efficiency of proposed new structures and are interested in the relation between yearly energy consumption and the number of square feet of building shell. The table on p. 552 lists the energy consumption in British thermal units (a BTU is the amount of heat required to raise 1 pound of water 1°F) for 22 buildings that were all subjected to the same climatic conditions. The SAS printout that fits the straight-line model relating BTU consumption, y, to building shell area, x, is shown on p. 553
a. Find the least squares estimates of the intercept ßo and the slope ß1.
b. Investigate the usefulness of the model you develop positively linearly related to the shell area of the building? Test using a = .10.
c. Calculate the observed significance level of the test of part b using the printout. Interpret its value.
d. Find the coefficient of determination r2 and interpret its value.
e. A company wishes to build a new warehouse that will contain 8,000 square feet of shell area. Find the predicted value of energy consumption and a 95% prediction interval on the printout. Comment on the usefulness of this interval.
f. The application of the model you developed in part a Is yearly energy consummation to the warehouse problem of part e is appropriate only if certain assumptions can be made about the new warehouse. What are these assumptions?
