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Finding the Fourth Proportional to 426.20, 638.66 and 252.90

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Solution

The fourth proportional to 426.20, 638.66 and 252.90 is: 378.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.20 : 638.66 = 252.90 : x
  2. Step 2: Convert to fraction form
    426.20/638.66 = 252.90/x
  3. Step 3: Cross multiply
    426.20x = 638.66 × 252.90
  4. Step 4: Simplify right side
    426.20x = 161,517.11
  5. Step 5: Solve for x
    x = 161,517.11/426.20
  6. Step 6: Final answer
    x = 378.97

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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.