1. Learning the mechanics. Do the data provide suf?cient evidence to indicate that β1 differs from 0 for the least squares analyses in the following exercises? Use α = .05.
2. Predicting home sales price. Refer to the data on sale prices and total appraised values of 76 residential properties in an upscale Tampa, Florida, neighborhood. An SPSS simple linear regression printout for the analysis is reproduced at the bottom of the page.
(a) Use the printout to determine whether there is a positive linear relationship between appraised property value x and sale price y for residential properties sold in this neighborhood. That is, determine if there is suf?cient evidence (at α = .01) to indicate that β1, the slope of the straight-line model, is positive.
(b) Find a 95% con?dence interval for the slope, β1, on the printout. Interpret the result practically.
(c) What can be done to obtain a narrower con?dence interval in part b?