21. Excel's Solver is used in a time-series weighted moving average problem to: a. Predict estimates for more than one period into the future c. Maximize the MSE b. Minimize the mean square error (MSE) d. None of the above 4 22. Regarding regression analysis involving only one independent variable: a. The best method for solving is a visual fit of a line to the data; b. The best method for solving requires a hyperplane fit to the data. c. The least squares method is mathematically the best way to apply it; d. The dependent variable is used to predict the value of the independent variable. 23. The least squares method is based upon: a. Minimizing the unexplained variation. b. Maximizing the unexplained variation. c. Minimizing the explained variation. d. Maximizing the total variation. 24. Given a regression cost function, y= 20 + 4x with a standard error of $6.80, and x represents the activity of direct labor hours, what is the estimated cost when x = 15? a. $15.60 b. $31.20 c. $160.00 d. $ 80.00