The article “Characterization of Highway Runoff in Austin, Texas, Area” (J. of Envir. Engr., 1998: 131-137) gave data on ...

The article “Characterization of Highway Runoff in Austin, Texas, Area” (J. of Envir. Engr., 1998: 131-137) gave data on rainfall volume (m3 ) and runoff volume (m3 ) measured on 30 different days for a particular location. We would like to determine how the runoff volume is affected by rainfall volume. Summary statistics of data are: x = 53.2, sx = 38.3, y = 42.9, sy = 32.1, n = 30. 1. In view of the question we want to answer, what is the predictor variable, and what is the response variable? 2. Suppose that the correlation coefficient between the rainfall volume and the runoff volume is r = 0.89. Find the least squares regression line equation. 3. What is proportion of variation in the runoff volume explained by the rainfall volume?