Free Resgonse Questions on Linear Regression 1. The National Directory of Magazines tracks the number of magazines published in the United States each year. An analysis of data from 1988 to 200? gives the following computer output. The dates were recorded as years since 1988. Thus, the year 1988 was recorded as year 0. A residual plot (not shown) showed no pattern. Predictor Cocf StDev T P Constant 13549.9 2.31 71.?9 0.000 Years 325.39 0.1950 10.0 0.000 S = 836.2 RSq = 84.8% RSq (adj) = 80.6% (a) What is the value of the slope of the least squares regression line? Interpret the slope in the context of this situation. (b) What is the value of the y-intercept of the least squares regression line? Interpret the y-intercept in the context of this situation. (c) Predict the number of magazines published in the United States in 1999. (d) What is the value of the correlation coefcient for number of magazines published in the US and years since 1988'? Interpret this correlation