why is it 36? can someone explain the steps and what they did

Innova Discs has two divisions-Standard and Premium. Each division has hundreds of different types of golf discs and disc golf products. The following information is available: Standard Division Total Premium Division Sales $600,000 $400,000 $1,000,000 280,000 Variable costs 360,000 Contribution margin $240,000 $120,000 Total fixed costs $270,000 What is the weighted average contribution margin ratio? 36%