Home / 78-86

Finding the Third Proportional to 78 and 86

Calculator

Solution

The third proportional to 78 and 86 is: 94.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    78 : 86 = 86 : x
  2. Step 2: Convert to fraction form
    78/86 = 86/x
  3. Step 3: Cross multiply
    78x = 86 × 86
  4. Step 4: Simplify right side
    78x = 7,396
  5. Step 5: Solve for x
    x = 7,396/78
  6. Step 6: Final answer
    x = 94.82

Related Problems

Find third proportional to 39 and 43
Half scale
Find third proportional to 156 and 172
Double scale
Find third proportional to 80 and 88
Similar ratio
Find third proportional to 117 and 129
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.10) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.