Home / 90-109.75

Finding the Third Proportional to 90 and 109.75

Calculator

Solution

The third proportional to 90 and 109.75 is: 133.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    90 : 109.75 = 109.75 : x
  2. Step 2: Convert to fraction form
    90/109.75 = 109.75/x
  3. Step 3: Cross multiply
    90x = 109.75 × 109.75
  4. Step 4: Simplify right side
    90x = 12,045.06
  5. Step 5: Solve for x
    x = 12,045.06/90
  6. Step 6: Final answer
    x = 133.83

Related Problems

Find third proportional to 45 and 54.88
Half scale
Find third proportional to 180 and 219.50
Double scale
Find third proportional to 92 and 112
Similar ratio
Find third proportional to 135 and 164.63
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.22) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.