Home / 77.75-138.75

Finding the Third Proportional to 77.75 and 138.75

Calculator

Solution

The third proportional to 77.75 and 138.75 is: 247.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.75 : 138.75 = 138.75 : x
  2. Step 2: Convert to fraction form
    77.75/138.75 = 138.75/x
  3. Step 3: Cross multiply
    77.75x = 138.75 × 138.75
  4. Step 4: Simplify right side
    77.75x = 19,251.56
  5. Step 5: Solve for x
    x = 19,251.56/77.75
  6. Step 6: Final answer
    x = 247.61

Related Problems

Find third proportional to 38.88 and 69.38
Half scale
Find third proportional to 155.50 and 277.50
Double scale
Find third proportional to 80 and 142
Similar ratio
Find third proportional to 116.63 and 208.13
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.78) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.