If yesterday's price was the regular price then the equation $217=62%x can be used to solve for x. so x = $217/0.62=$350. To check the answer, multiply $350 by 0.62 = $217. In other words, x is the unknown regular price so 0.62 times x = $217 and then cross multiplying means dividing $217 by 0.62, to get the answer.