Home / 422.50-520

Finding the Third Proportional to 422.50 and 520

Calculator

Solution

The third proportional to 422.50 and 520 is: 640

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.50 : 520 = 520 : x
  2. Step 2: Convert to fraction form
    422.50/520 = 520/x
  3. Step 3: Cross multiply
    422.50x = 520 × 520
  4. Step 4: Simplify right side
    422.50x = 270,400
  5. Step 5: Solve for x
    x = 270,400/422.50
  6. Step 6: Final answer
    x = 640

Related Problems

Find third proportional to 211.25 and 260
Half scale
Find third proportional to 845 and 1,040
Double scale
Find third proportional to 425 and 522
Similar ratio
Find third proportional to 633.75 and 780
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.23) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.