Home / 91-109

Finding the Third Proportional to 91 and 109

Calculator

Solution

The third proportional to 91 and 109 is: 130.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    91 : 109 = 109 : x
  2. Step 2: Convert to fraction form
    91/109 = 109/x
  3. Step 3: Cross multiply
    91x = 109 × 109
  4. Step 4: Simplify right side
    91x = 11,881
  5. Step 5: Solve for x
    x = 11,881/91
  6. Step 6: Final answer
    x = 130.56

Related Problems

Find third proportional to 45.50 and 54.50
Half scale
Find third proportional to 182 and 218
Double scale
Find third proportional to 93 and 111
Similar ratio
Find third proportional to 136.50 and 163.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.