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Finding the Fourth Proportional to 425.57, 638.36 and 209.30

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Solution

The fourth proportional to 425.57, 638.36 and 209.30 is: 313.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.57 : 638.36 = 209.30 : x
  2. Step 2: Convert to fraction form
    425.57/638.36 = 209.30/x
  3. Step 3: Cross multiply
    425.57x = 638.36 × 209.30
  4. Step 4: Simplify right side
    425.57x = 133,607.70
  5. Step 5: Solve for x
    x = 133,607.70/425.57
  6. Step 6: Final answer
    x = 313.95

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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.