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Finding the Fourth Proportional to 819.62, 1,227.80 and 387.08

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Solution

The fourth proportional to 819.62, 1,227.80 and 387.08 is: 579.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.62 : 1,227.80 = 387.08 : x
  2. Step 2: Convert to fraction form
    819.62/1,227.80 = 387.08/x
  3. Step 3: Cross multiply
    819.62x = 1,227.80 × 387.08
  4. Step 4: Simplify right side
    819.62x = 475,248.75
  5. Step 5: Solve for x
    x = 475,248.75/819.62
  6. Step 6: Final answer
    x = 579.84

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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.