Question

solve for r in the proportion
\frac{396}{r} = \frac{220}{50}

r = \square

submit

Explanation:

Step1: Cross - multiply the proportion

Given the proportion \(\frac{396}{r}=\frac{220}{50}\), cross - multiplying gives us \(220\times r = 396\times50\).

Step2: Calculate the right - hand side

First, calculate \(396\times50\). We know that \(396\times50=(400 - 4)\times50=400\times50-4\times50 = 20000-200 = 19800\). So the equation becomes \(220r=19800\).

Step3: Solve for \(r\)

To solve for \(r\), divide both sides of the equation \(220r = 19800\) by 220. That is \(r=\frac{19800}{220}\). Simplifying, we can divide numerator and denominator by 220: \(r = 90\).

Answer:

\(90\)