Stacy, Inc., produces a product using a process that allows for substitution between two materials, Alpha and Beta. The company has the following direct materials data for its product: Standard costs for one unit of output Alpha Beta 42 units of input at 84 units of input at $6.00 $8.50 The company had the following results in June Units of output produced 2,100 units Materials purchased and used Alpha Beta 95,700 units at $5.50 168,900 units at $9.00 Required a. Compute materials price and efficiency variances. (Do not round intermediate calculations. Indicate the effect of each variance by selecting "F" for favorable, or "U" for unfavorable. If there is no effect, do not select either option.) Alpha Beta Total Materials price Efficiency variances b. Compute materials mix and yield variances. (Do not round intermediate calculations. Indicate the effect of each variance by selecting "F" or favorable, or "U" for unfavorable If there is no effect, do not select either option.) Alpha Beta Total Materials mix Yield variances