Tom and Lynda own Hercules Health Club. For the month of April, they had forecasted gym membership at 700 individual members and 300 family memberships. Individual members pay $100 per month and families pay $150 per month. Variable costs are $35 and $60 per month, respectively. Actual results for April show membership at 750 individual and 250 family members.

Required:
a. Determine Hercules’ sales volume variance.
b. Decompose the sales volume variance into a sales mix variance and a sales quantity variance.
c. Why did Hercules’ contribution decrease even though the total memberships were the same?