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Finding the Fourth Proportional to 425.31, 638.12 and 219.75

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Solution

The fourth proportional to 425.31, 638.12 and 219.75 is: 329.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.31 : 638.12 = 219.75 : x
  2. Step 2: Convert to fraction form
    425.31/638.12 = 219.75/x
  3. Step 3: Cross multiply
    425.31x = 638.12 × 219.75
  4. Step 4: Simplify right side
    425.31x = 140,225.03
  5. Step 5: Solve for x
    x = 140,225.03/425.31
  6. Step 6: Final answer
    x = 329.70

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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.