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Finding the Fourth Proportional to 425.85, 638.24 and 220.11

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Solution

The fourth proportional to 425.85, 638.24 and 220.11 is: 329.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.85 : 638.24 = 220.11 : x
  2. Step 2: Convert to fraction form
    425.85/638.24 = 220.11/x
  3. Step 3: Cross multiply
    425.85x = 638.24 × 220.11
  4. Step 4: Simplify right side
    425.85x = 140,481.91
  5. Step 5: Solve for x
    x = 140,481.91/425.85
  6. Step 6: Final answer
    x = 329.89

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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.