The (partial) cost sheet for the single product manufactured at Vienna Company follows. Direct labor Variable overhead Fixed overhead (23 hours @ $25) (23 hours @ $2) (23 hours @ $4) $575 46 92 The master budget level of production is 94,000 direct-labor hours, which is also the production volume used to compute the fixed overhead application rate. Other information available for operations over the past accounting period include the following. Actual variable overhead incurred Actual fixed overhead incurred Direct labor efficiency variance Variable overhead price variance $144,000 392,400 174,000 U 42,000 F Required: a. What was the variable overhead efficiency variance? b. What was the fixed overhead price variance? c. What was the fixed overhead production volume variance? (For all requirements, 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.)