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Finding the Fourth Proportional to 1,319.12, 1,819.96 and 787.76

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Solution

The fourth proportional to 1,319.12, 1,819.96 and 787.76 is: 1,086.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,319.12 : 1,819.96 = 787.76 : x
  2. Step 2: Convert to fraction form
    1,319.12/1,819.96 = 787.76/x
  3. Step 3: Cross multiply
    1,319.12x = 1,819.96 × 787.76
  4. Step 4: Simplify right side
    1,319.12x = 1,433,691.69
  5. Step 5: Solve for x
    x = 1,433,691.69/1,319.12
  6. Step 6: Final answer
    x = 1,086.85

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.