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Finding the Fourth Proportional to 636.20, 878 and 387.46

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Solution

The fourth proportional to 636.20, 878 and 387.46 is: 534.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.20 : 878 = 387.46 : x
  2. Step 2: Convert to fraction form
    636.20/878 = 387.46/x
  3. Step 3: Cross multiply
    636.20x = 878 × 387.46
  4. Step 4: Simplify right side
    636.20x = 340,189.88
  5. Step 5: Solve for x
    x = 340,189.88/636.20
  6. Step 6: Final answer
    x = 534.72

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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.