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Finding the Fourth Proportional to 427.70, 638.97 and 272.31

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Solution

The fourth proportional to 427.70, 638.97 and 272.31 is: 406.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.70 : 638.97 = 272.31 : x
  2. Step 2: Convert to fraction form
    427.70/638.97 = 272.31/x
  3. Step 3: Cross multiply
    427.70x = 638.97 × 272.31
  4. Step 4: Simplify right side
    427.70x = 173,997.92
  5. Step 5: Solve for x
    x = 173,997.92/427.70
  6. Step 6: Final answer
    x = 406.83

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.