Home / 47.57-81.21

Finding the Third Proportional to 47.57 and 81.21

Calculator

Solution

The third proportional to 47.57 and 81.21 is: 138.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.57 : 81.21 = 81.21 : x
  2. Step 2: Convert to fraction form
    47.57/81.21 = 81.21/x
  3. Step 3: Cross multiply
    47.57x = 81.21 × 81.21
  4. Step 4: Simplify right side
    47.57x = 6,595.22
  5. Step 5: Solve for x
    x = 6,595.22/47.57
  6. Step 6: Final answer
    x = 138.65

Related Problems

Find third proportional to 23.78 and 40.61
Half scale
Find third proportional to 95.13 and 162.42
Double scale
Find third proportional to 50 and 85
Similar ratio
Find third proportional to 71.35 and 121.82
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.71) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.