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Finding the Fourth Proportional to 426.15, 638.82 and 209.61

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Solution

The fourth proportional to 426.15, 638.82 and 209.61 is: 314.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.15 : 638.82 = 209.61 : x
  2. Step 2: Convert to fraction form
    426.15/638.82 = 209.61/x
  3. Step 3: Cross multiply
    426.15x = 638.82 × 209.61
  4. Step 4: Simplify right side
    426.15x = 133,903.06
  5. Step 5: Solve for x
    x = 133,903.06/426.15
  6. Step 6: Final answer
    x = 314.22

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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.