The Octova Corporation Manufactures Two Types of Vacuum Cleaners: the ZENITH

The Octova Corporation manufactures two types of vacuum cleaners: the ZENITH for commercial building use and the House-Helper for residences.Budgeted and actual operating data for the year 20X5 are as follows:
$$\begin{array}{l}\begin{array} { l r r r } \text { Static Budget } & \text { ZENITH } & \text { House-Helper } & \text { Total } \\\hline \text { Number sold } & 20,000 & 80,000 & 100,000\end{array}\\\text { Contribution margin } \quad \$ 4,600,000 \quad \$ 15,200,000 \quad \$ 19,800,000\\\\\begin{array} { l r r r } \text { Actual Results } & \text { ZENITH } & \text { House-Helper } & \text { Total } \\\hline\text { Number sold } & 21,500 & 60,000 & 81,500 \\\text { Contribution margin } & \$ 6,665,000 & \$ 13,200,000 & \$ 19,865,000\end{array}\end{array}$$ Required:
a.Calculate the contribution margin for the flexible budget.
b.Determine the total static-budget variance,the total flexible-budget variance,and the total sales-volume variance in terms of the contribution margin.