The (partial) cost sheet for the single product manufactured at Vienna Company follows. Direct labor (22 hours @ $25) $ 550 Variable overhead (22 hours @ $2) 44 Fixed overhead (22 hours @ $4) 88 The master budget level of production is 92,000 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 $ 142,000 Actual fixed overhead incurred 384,200 Direct labor efficiency variance 172,000 U Variable overhead price variance 40,000 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.)