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Finding the Fourth Proportional to 425.74, 638.34 and 279.31

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Solution

The fourth proportional to 425.74, 638.34 and 279.31 is: 418.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.74 : 638.34 = 279.31 : x
  2. Step 2: Convert to fraction form
    425.74/638.34 = 279.31/x
  3. Step 3: Cross multiply
    425.74x = 638.34 × 279.31
  4. Step 4: Simplify right side
    425.74x = 178,292.10
  5. Step 5: Solve for x
    x = 178,292.10/425.74
  6. Step 6: Final answer
    x = 418.78

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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.