Home / 66.38-138.38

Finding the Third Proportional to 66.38 and 138.38

Calculator

Solution

The third proportional to 66.38 and 138.38 is: 288.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.38 : 138.38 = 138.38 : x
  2. Step 2: Convert to fraction form
    66.38/138.38 = 138.38/x
  3. Step 3: Cross multiply
    66.38x = 138.38 × 138.38
  4. Step 4: Simplify right side
    66.38x = 19,147.64
  5. Step 5: Solve for x
    x = 19,147.64/66.38
  6. Step 6: Final answer
    x = 288.48

Related Problems

Find third proportional to 33.19 and 69.19
Half scale
Find third proportional to 132.75 and 276.75
Double scale
Find third proportional to 68 and 143
Similar ratio
Find third proportional to 99.56 and 207.56
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.08) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.