Home / 30.80-66.80

Finding the Third Proportional to 30.80 and 66.80

Calculator

Solution

The third proportional to 30.80 and 66.80 is: 144.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.80 : 66.80 = 66.80 : x
  2. Step 2: Convert to fraction form
    30.80/66.80 = 66.80/x
  3. Step 3: Cross multiply
    30.80x = 66.80 × 66.80
  4. Step 4: Simplify right side
    30.80x = 4,461.82
  5. Step 5: Solve for x
    x = 4,461.82/30.80
  6. Step 6: Final answer
    x = 144.88

Related Problems

Find third proportional to 15.40 and 33.40
Half scale
Find third proportional to 61.59 and 133.59
Double scale
Find third proportional to 33 and 71
Similar ratio
Find third proportional to 46.20 and 100.20
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.17) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.