Compute the following variances for May:

a$.$Materials price and quantity variances.

b$.$Labor rate and efficiency variances.

c$.$Variable overhead rate and efficiency variances.

$2.$How much of the $$0\mathrm{.}44$ excess unit cost is traceable to each of the variances computed in requirement $1.$

$3.$How much of the $$0\mathrm{.}44$ excess unit cost is traceable to apparent inefficient use of labor time?