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Finding the Fourth Proportional to 425.90, 638.53 and 209.66

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Solution

The fourth proportional to 425.90, 638.53 and 209.66 is: 314.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.90 : 638.53 = 209.66 : x
  2. Step 2: Convert to fraction form
    425.90/638.53 = 209.66/x
  3. Step 3: Cross multiply
    425.90x = 638.53 × 209.66
  4. Step 4: Simplify right side
    425.90x = 133,874.20
  5. Step 5: Solve for x
    x = 133,874.20/425.90
  6. Step 6: Final answer
    x = 314.33

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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.