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Finding the Fourth Proportional to 819.31, 1,228.78 and 234.30

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Solution

The fourth proportional to 819.31, 1,228.78 and 234.30 is: 351.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.31 : 1,228.78 = 234.30 : x
  2. Step 2: Convert to fraction form
    819.31/1,228.78 = 234.30/x
  3. Step 3: Cross multiply
    819.31x = 1,228.78 × 234.30
  4. Step 4: Simplify right side
    819.31x = 287,906.74
  5. Step 5: Solve for x
    x = 287,906.74/819.31
  6. Step 6: Final answer
    x = 351.40

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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.