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Finding the Fourth Proportional to 1,318.81, 1,819.80 and 787.62

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Solution

The fourth proportional to 1,318.81, 1,819.80 and 787.62 is: 1,086.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,318.81 : 1,819.80 = 787.62 : x
  2. Step 2: Convert to fraction form
    1,318.81/1,819.80 = 787.62/x
  3. Step 3: Cross multiply
    1,318.81x = 1,819.80 × 787.62
  4. Step 4: Simplify right side
    1,318.81x = 1,433,321.02
  5. Step 5: Solve for x
    x = 1,433,321.02/1,318.81
  6. Step 6: Final answer
    x = 1,086.83

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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.