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Finding the Fourth Proportional to 425.84, 638.60 and 209.30

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Solution

The fourth proportional to 425.84, 638.60 and 209.30 is: 313.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.84 : 638.60 = 209.30 : x
  2. Step 2: Convert to fraction form
    425.84/638.60 = 209.30/x
  3. Step 3: Cross multiply
    425.84x = 638.60 × 209.30
  4. Step 4: Simplify right side
    425.84x = 133,658.98
  5. Step 5: Solve for x
    x = 133,658.98/425.84
  6. Step 6: Final answer
    x = 313.87

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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.