e) (2 points) Interpret the value of R-. f) (2 points) Use the model developed in part b to estimate per capita retail sales in Alexandria, VA at levels of x) = 1.199, x, =32.508, x; =16.978 and x, =91. (!Do not use the value of *; if you rejected the null hypothesis in part d!) :) (2 points) Find the estimate of o, the standard deviation of the random error term, and interpret its value