Home / 84-126

Finding the Third Proportional to 84 and 126

Calculator

Solution

The third proportional to 84 and 126 is: 189

Step by Step Solution

  1. Step 1: Write the proportion equation
    84 : 126 = 126 : x
  2. Step 2: Convert to fraction form
    84/126 = 126/x
  3. Step 3: Cross multiply
    84x = 126 × 126
  4. Step 4: Simplify right side
    84x = 15,876
  5. Step 5: Solve for x
    x = 15,876/84
  6. Step 6: Final answer
    x = 189

Related Problems

Find third proportional to 42 and 63
Half scale
Find third proportional to 168 and 252
Double scale
Find third proportional to 86 and 129
Similar ratio
Find third proportional to 126 and 189
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.