Affordable Electronics Inc. manufactures medium-quality, reasonably priced wireless speakers for home use. The company uses standards to control its costs. The labour standards that have been set for one speaker are as follows: Standard Hours 18 minutes (0.30 hours) Standard Rate per Hour $10.00 Standard Cost $3.00 During July, 6,550 hours of direct labour time were recorded to make 21,000 units. The direct labour cost totalled $69,430 for the month. 3. The budgeted variable manufacturing overhead rate is $4.00 per direct labour-hour. During July, the company incurred $27,510 in variable manufacturing overhead cost. Compute the variable overhead spending and efficiency variances for the month. (Indicate the effect of each variance by selecting "F" for favourable, "U" for unfavourable, and "None" for no effect (i.e., zero variance).) Variable overhead spending variance Variable overhead efficiency variance