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Finding the Fourth Proportional to 220.20, 329.85 and 138.75

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Solution

The fourth proportional to 220.20, 329.85 and 138.75 is: 207.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.20 : 329.85 = 138.75 : x
  2. Step 2: Convert to fraction form
    220.20/329.85 = 138.75/x
  3. Step 3: Cross multiply
    220.20x = 329.85 × 138.75
  4. Step 4: Simplify right side
    220.20x = 45,766.69
  5. Step 5: Solve for x
    x = 45,766.69/220.20
  6. Step 6: Final answer
    x = 207.84

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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.