Calista & Lane, CPA's set the following standard for its inventory audit of Triumph Co.; 350 hours at an average hourly billing rate of $ 250. The firm actually worked 330 hours during the inventory audit process. The total labor variance for the audit was $ 3,500 unfavorable. a. Compute the total actual payroll. b. Compute the labor efficiency variance. c. Compute the labor rate variance. d. Prepare the entry to assign labor cost to inventory, record the labor variances, and accrue payroll costs. e. write a memo to the appropriate personnel regarding feedback about the labor efficiency variance. The memo should also offer a brief explanation that is consistent with the labor rate and efficiency variances.