Stearn and Company makes a lubricating oil using two grades of petroleum (Alpha and Beta). Within certain limits, the two grades can substitute for one another, so the actual mix of inputs often differs from the standard mix. Stearn holds no materials inventories. The standard cost of a unit of output follows. A total of 60,000 units were produced during February. The actual inputs purchased and used during February were as follows: Required: Prepare a complete materials variance analysis showing the materials price variance, the materials efficiency variance, the materials mix variance, and the materials yield variance. Note: 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