Home / 210-309

Finding the Third Proportional to 210 and 309

Calculator

Solution

The third proportional to 210 and 309 is: 454.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    210 : 309 = 309 : x
  2. Step 2: Convert to fraction form
    210/309 = 309/x
  3. Step 3: Cross multiply
    210x = 309 × 309
  4. Step 4: Simplify right side
    210x = 95,481
  5. Step 5: Solve for x
    x = 95,481/210
  6. Step 6: Final answer
    x = 454.67

Related Problems

Find third proportional to 105 and 154.50
Half scale
Find third proportional to 420 and 618
Double scale
Find third proportional to 212 and 312
Similar ratio
Find third proportional to 315 and 463.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.47) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.