Home / 409-665

Finding the Third Proportional to 409 and 665

Calculator

Solution

The third proportional to 409 and 665 is: 1,081.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    409 : 665 = 665 : x
  2. Step 2: Convert to fraction form
    409/665 = 665/x
  3. Step 3: Cross multiply
    409x = 665 × 665
  4. Step 4: Simplify right side
    409x = 442,225
  5. Step 5: Solve for x
    x = 442,225/409
  6. Step 6: Final answer
    x = 1,081.23

Related Problems

Find third proportional to 204.50 and 332.50
Half scale
Find third proportional to 818 and 1,330
Double scale
Find third proportional to 411 and 668
Similar ratio
Find third proportional to 613.50 and 997.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.63) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.