Home / 318-409

Finding the Third Proportional to 318 and 409

Calculator

Solution

The third proportional to 318 and 409 is: 526.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    318 : 409 = 409 : x
  2. Step 2: Convert to fraction form
    318/409 = 409/x
  3. Step 3: Cross multiply
    318x = 409 × 409
  4. Step 4: Simplify right side
    318x = 167,281
  5. Step 5: Solve for x
    x = 167,281/318
  6. Step 6: Final answer
    x = 526.04

Related Problems

Find third proportional to 159 and 204.50
Half scale
Find third proportional to 636 and 818
Double scale
Find third proportional to 320 and 412
Similar ratio
Find third proportional to 477 and 613.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.29) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.