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Finding the Fourth Proportional to 819.70, 1,226.84 and 511.78

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Solution

The fourth proportional to 819.70, 1,226.84 and 511.78 is: 765.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.70 : 1,226.84 = 511.78 : x
  2. Step 2: Convert to fraction form
    819.70/1,226.84 = 511.78/x
  3. Step 3: Cross multiply
    819.70x = 1,226.84 × 511.78
  4. Step 4: Simplify right side
    819.70x = 627,872.18
  5. Step 5: Solve for x
    x = 627,872.18/819.70
  6. Step 6: Final answer
    x = 765.98

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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.