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Finding the Fourth Proportional to 819.86, 1,230.10 and 381.33

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Solution

The fourth proportional to 819.86, 1,230.10 and 381.33 is: 572.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.86 : 1,230.10 = 381.33 : x
  2. Step 2: Convert to fraction form
    819.86/1,230.10 = 381.33/x
  3. Step 3: Cross multiply
    819.86x = 1,230.10 × 381.33
  4. Step 4: Simplify right side
    819.86x = 469,073.08
  5. Step 5: Solve for x
    x = 469,073.08/819.86
  6. Step 6: Final answer
    x = 572.14

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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.