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Finding the Fourth Proportional to 819.36, 1,229.04 and 408.12

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Solution

The fourth proportional to 819.36, 1,229.04 and 408.12 is: 612.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.36 : 1,229.04 = 408.12 : x
  2. Step 2: Convert to fraction form
    819.36/1,229.04 = 408.12/x
  3. Step 3: Cross multiply
    819.36x = 1,229.04 × 408.12
  4. Step 4: Simplify right side
    819.36x = 501,595.80
  5. Step 5: Solve for x
    x = 501,595.80/819.36
  6. Step 6: Final answer
    x = 612.18

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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.