Stacy, Inc., produces a product using a process that allows for substitution between two materials, Alpha and Beta. The company has the following direct materials data for its product.

Standard costs for one unit of output

Alpha $24$ units of input at $ $8\mathrm{.}00$

Beta $48$ units of input at $ $16\mathrm{.}50$

The company had the following results in June.

Units of output produced $3,800$ units

Materials purchased and used

Alpha $99,200$ units at $ $7\mathrm{.}50$

Beta $174,400$ units at $ $16\mathrm{.}80$

Required:

a$.$ Compute materials price and efficiency variances.

b$.$ Compute materials mix and yield variances.