Home / 204.30-306.20-139.30

Finding the Fourth Proportional to 204.30, 306.20 and 139.30

Calculator

Solution

The fourth proportional to 204.30, 306.20 and 139.30 is: 208.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    204.30 : 306.20 = 139.30 : x
  2. Step 2: Convert to fraction form
    204.30/306.20 = 139.30/x
  3. Step 3: Cross multiply
    204.30x = 306.20 × 139.30
  4. Step 4: Simplify right side
    204.30x = 42,653.66
  5. Step 5: Solve for x
    x = 42,653.66/204.30
  6. Step 6: Final answer
    x = 208.78

Related Problems

Find fourth proportional to 102.15, 153.10 and 69.65
Half scale
Find fourth proportional to 408.60, 612.40 and 278.60
Double scale
Find fourth proportional to 205.30, 307.70 and 140.30
Similar ratio
Find fourth proportional to 306.45, 459.30 and 208.95
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.