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Finding the Fourth Proportional to 636.69, 878.61 and 387.92

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Solution

The fourth proportional to 636.69, 878.61 and 387.92 is: 535.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.69 : 878.61 = 387.92 : x
  2. Step 2: Convert to fraction form
    636.69/878.61 = 387.92/x
  3. Step 3: Cross multiply
    636.69x = 878.61 × 387.92
  4. Step 4: Simplify right side
    636.69x = 340,830.39
  5. Step 5: Solve for x
    x = 340,830.39/636.69
  6. Step 6: Final answer
    x = 535.32

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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.