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Finding the Fourth Proportional to 425.86, 638.31 and 209.59

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Solution

The fourth proportional to 425.86, 638.31 and 209.59 is: 314.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.86 : 638.31 = 209.59 : x
  2. Step 2: Convert to fraction form
    425.86/638.31 = 209.59/x
  3. Step 3: Cross multiply
    425.86x = 638.31 × 209.59
  4. Step 4: Simplify right side
    425.86x = 133,783.39
  5. Step 5: Solve for x
    x = 133,783.39/425.86
  6. Step 6: Final answer
    x = 314.15

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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.