Exercise 17-21 (Algo) Variable Cost Variances: Materials Purchased and Materials Used Are Not Equal (LO172) In reviewing activity for July, the controller of Mathis, Inc, collected the foliowing data concerning direct materiais. Required: Compute the direct materials cost variances. (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.) Exercise 17-21 (Algo) Variable Cost Variances: Materials Purchased and Materials Used Are Not Equal (LO172) In reviewing activity for July, the controller of Mathis, Inc, collected the foliowing data concerning direct materiais. Required: Compute the direct materials cost variances. (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.)