Home / 280-409

Finding the Third Proportional to 280 and 409

Calculator

Solution

The third proportional to 280 and 409 is: 597.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    280 : 409 = 409 : x
  2. Step 2: Convert to fraction form
    280/409 = 409/x
  3. Step 3: Cross multiply
    280x = 409 × 409
  4. Step 4: Simplify right side
    280x = 167,281
  5. Step 5: Solve for x
    x = 167,281/280
  6. Step 6: Final answer
    x = 597.43

Related Problems

Find third proportional to 140 and 204.50
Half scale
Find third proportional to 560 and 818
Double scale
Find third proportional to 282 and 412
Similar ratio
Find third proportional to 420 and 613.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.46) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.