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Finding the Fourth Proportional to 725.28, 1,086.09 and 687

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Solution

The fourth proportional to 725.28, 1,086.09 and 687 is: 1,028.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    725.28 : 1,086.09 = 687 : x
  2. Step 2: Convert to fraction form
    725.28/1,086.09 = 687/x
  3. Step 3: Cross multiply
    725.28x = 1,086.09 × 687
  4. Step 4: Simplify right side
    725.28x = 746,143.83
  5. Step 5: Solve for x
    x = 746,143.83/725.28
  6. Step 6: Final answer
    x = 1,028.77

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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.