In an investigation of environmental causes of disease, data were collected on the annual mortality rate (deaths per 100,000) for males in 61 large towns in England. In addition, water hardness was recorded as the calcium concentration (parts per million or ppm) in the drinking water. The following regression equation was obtained: Mortality = 1676.36 - 3.226 (calcium) . Also, the power prediction characteristic R2 =42.9%. (a) Identify and interpret the slope of the line. (b) Calculate the correlation coefficient