20. (10 points) Bolt manufactures steel bolts for commercial building construction. Bolt makes three types of bolts 1/8-inch, 1/4 inch and 1/2 inch. Actual and Budget operating data by product for the most recent reporting period are as follows: a. Calculate the sales-mix variance for each product and in total. b. Calculate the sales-quantity variance for each product and in total. c. Provide an explanation for what is driving the sales-mix variance. Discuss an issue, not the numerical variance amounts