Home / 75.50-128.75

Finding the Third Proportional to 75.50 and 128.75

Calculator

Solution

The third proportional to 75.50 and 128.75 is: 219.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.50 : 128.75 = 128.75 : x
  2. Step 2: Convert to fraction form
    75.50/128.75 = 128.75/x
  3. Step 3: Cross multiply
    75.50x = 128.75 × 128.75
  4. Step 4: Simplify right side
    75.50x = 16,576.56
  5. Step 5: Solve for x
    x = 16,576.56/75.50
  6. Step 6: Final answer
    x = 219.56

Related Problems

Find third proportional to 37.75 and 64.38
Half scale
Find third proportional to 151 and 257.50
Double scale
Find third proportional to 78 and 132
Similar ratio
Find third proportional to 113.25 and 193.13
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.71) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.