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Finding the Fourth Proportional to 819.92, 1,230.17 and 381.38

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Solution

The fourth proportional to 819.92, 1,230.17 and 381.38 is: 572.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.92 : 1,230.17 = 381.38 : x
  2. Step 2: Convert to fraction form
    819.92/1,230.17 = 381.38/x
  3. Step 3: Cross multiply
    819.92x = 1,230.17 × 381.38
  4. Step 4: Simplify right side
    819.92x = 469,162.23
  5. Step 5: Solve for x
    x = 469,162.23/819.92
  6. Step 6: Final answer
    x = 572.20

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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.