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Finding the Fourth Proportional to 425.60, 638.80 and 209.32

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Solution

The fourth proportional to 425.60, 638.80 and 209.32 is: 314.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.60 : 638.80 = 209.32 : x
  2. Step 2: Convert to fraction form
    425.60/638.80 = 209.32/x
  3. Step 3: Cross multiply
    425.60x = 638.80 × 209.32
  4. Step 4: Simplify right side
    425.60x = 133,713.62
  5. Step 5: Solve for x
    x = 133,713.62/425.60
  6. Step 6: Final answer
    x = 314.18

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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.