Home / 408.80-520.17

Finding the Third Proportional to 408.80 and 520.17

Calculator

Solution

The third proportional to 408.80 and 520.17 is: 661.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.80 : 520.17 = 520.17 : x
  2. Step 2: Convert to fraction form
    408.80/520.17 = 520.17/x
  3. Step 3: Cross multiply
    408.80x = 520.17 × 520.17
  4. Step 4: Simplify right side
    408.80x = 270,578.78
  5. Step 5: Solve for x
    x = 270,578.78/408.80
  6. Step 6: Final answer
    x = 661.89

Related Problems

Find third proportional to 204.40 and 260.09
Half scale
Find third proportional to 817.59 and 1,040.34
Double scale
Find third proportional to 411 and 523
Similar ratio
Find third proportional to 613.20 and 780.26
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.27) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.