Robinson Company has two products, A and B$.$ Robinson$$s budget for August follows:

Master Budget

Product A Product B

Sales $ $240,000$ $ $300,000$

Variable cost $140,000180,000$

Contribution margin $ $100,000$ $ $120,000$

Fixed cost $80,00040,000$

Operating income $ $20,000$ $ $80,000$

Selling price $ $120$ $ $50$

On September $1,$ these operating results for August were reported:

Operating Results

Product A Product B

Sales $ $180,400$ $ $341,120$

Variable cost $106,600216,480$

Contribution margin $ $73,800$ $ $124,640$

Fixed cost $80,00040,000$

Operating income $ $(6,200)$ $ $84,640$

Units sold $1,6406,560$

Required:

$1.$ For each product, determine the following variances measured in dollars of contribution margin:

Product A Product B

a$.$ Flexible$-$budget variance

b$.$ Sales volume variance

c$.$ Sales quantity variance

d$.$ Sales mix variance