The contribution sales ratio is the contribution to the income of the company that each sale of a product has. Essentially, it is a factor or percentage that determines how much money the company earns for every extra dollar sold.
The contribution sales ratio is calculated by subtracting variable cost of sales from the sales revenue and dividing that number by the sales revenue. In this case, that comes out to the following:
(99 - 66)/(99) = 0.33, or 33%.
This means that for every dollar sold, the company earns 33 extra cents. I believe in an answer below, the educator accidentally swapped the sales in the denominator with variable costs, giving a higher contribution-sales ratio, but the steps are the same.
In that case, the company would break even when the sales tripled to the fixed costs, or at $1,350,000.