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Finding the Fourth Proportional to 636.34, 878.13 and 387.61

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Solution

The fourth proportional to 636.34, 878.13 and 387.61 is: 534.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.34 : 878.13 = 387.61 : x
  2. Step 2: Convert to fraction form
    636.34/878.13 = 387.61/x
  3. Step 3: Cross multiply
    636.34x = 878.13 × 387.61
  4. Step 4: Simplify right side
    636.34x = 340,371.97
  5. Step 5: Solve for x
    x = 340,371.97/636.34
  6. Step 6: Final answer
    x = 534.89

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.