A researcher wants to determine whether the rate of water flow (in liters per second) over an experimental soil bed can be used to predict the amount of soil washed away (in kilograms). The researcher measures the amount of soil washed away for various flow rates, and from these data calculates the least-squares regression line to be amount of eroded soil = 0.4 1.3 × (flow rate) The correlation between amount of eroded soil and flow rate would be A. 1/(1.3). B. 1.3. C. positive, but we cannot say what the exact value is. D. either positive or negative. It is impossible to say anything about the correlation from the information given.