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Finding the Fourth Proportional to 819.57, 1,229.49 and 408.72

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Solution

The fourth proportional to 819.57, 1,229.49 and 408.72 is: 613.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.57 : 1,229.49 = 408.72 : x
  2. Step 2: Convert to fraction form
    819.57/1,229.49 = 408.72/x
  3. Step 3: Cross multiply
    819.57x = 1,229.49 × 408.72
  4. Step 4: Simplify right side
    819.57x = 502,513.70
  5. Step 5: Solve for x
    x = 502,513.70/819.57
  6. Step 6: Final answer
    x = 613.14

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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.