An efficiency consultant determines that on the assembly line at stihl inc., there is a strong, negative, linear relationship between x=the number of consecutive hours a worker has been assembling chainsaws and y=the number of chainsaws he can produce in an hour. he finds that 70%of the variation in chainsaws produced per hour can be explained by the regression of y on x. which of the following is the best approximation of the correlation of x and y? a)-0.84, b) -0.7, c) -0.49, d) 0.49, e) 0.84