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Finding the Fourth Proportional to 425.61, 638.64 and 424.31

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Solution

The fourth proportional to 425.61, 638.64 and 424.31 is: 636.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.61 : 638.64 = 424.31 : x
  2. Step 2: Convert to fraction form
    425.61/638.64 = 424.31/x
  3. Step 3: Cross multiply
    425.61x = 638.64 × 424.31
  4. Step 4: Simplify right side
    425.61x = 270,978.15
  5. Step 5: Solve for x
    x = 270,978.15/425.61
  6. Step 6: Final answer
    x = 636.68

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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.