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Finding the Fourth Proportional to 425.87, 638.66 and 209.60

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Solution

The fourth proportional to 425.87, 638.66 and 209.60 is: 314.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.87 : 638.66 = 209.60 : x
  2. Step 2: Convert to fraction form
    425.87/638.66 = 209.60/x
  3. Step 3: Cross multiply
    425.87x = 638.66 × 209.60
  4. Step 4: Simplify right side
    425.87x = 133,860.47
  5. Step 5: Solve for x
    x = 133,860.47/425.87
  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.