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Finding the Fourth Proportional to 636.64, 878.28 and 387.92

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Solution

The fourth proportional to 636.64, 878.28 and 387.92 is: 535.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.64 : 878.28 = 387.92 : x
  2. Step 2: Convert to fraction form
    636.64/878.28 = 387.92/x
  3. Step 3: Cross multiply
    636.64x = 878.28 × 387.92
  4. Step 4: Simplify right side
    636.64x = 340,702.38
  5. Step 5: Solve for x
    x = 340,702.38/636.64
  6. Step 6: Final answer
    x = 535.16

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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.