Home / 81.75-90

Finding the Third Proportional to 81.75 and 90

Calculator

Solution

The third proportional to 81.75 and 90 is: 99.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.75 : 90 = 90 : x
  2. Step 2: Convert to fraction form
    81.75/90 = 90/x
  3. Step 3: Cross multiply
    81.75x = 90 × 90
  4. Step 4: Simplify right side
    81.75x = 8,100
  5. Step 5: Solve for x
    x = 8,100/81.75
  6. Step 6: Final answer
    x = 99.08

Related Problems

Find third proportional to 40.88 and 45
Half scale
Find third proportional to 163.50 and 180
Double scale
Find third proportional to 84 and 92
Similar ratio
Find third proportional to 122.63 and 135
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.