Hunter Family Instruments makes cellos. During the past year, the company made 6,400 cellos even though the budget planned for only 5,600. The company paid its workers an average of $15 per hour, which was $1 higher than the standard labor rate. The production manager budgets four direct labor hours per cello. During the year, a total of 24,320 direct labor hours were worked.

Required

a. Calculate the direct labor rate and efficiency variances.

b. What might have caused the variances you calculated?