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Finding the Fourth Proportional to 686.31, 1,027.85 and 557.79

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Solution

The fourth proportional to 686.31, 1,027.85 and 557.79 is: 835.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.31 : 1,027.85 = 557.79 : x
  2. Step 2: Convert to fraction form
    686.31/1,027.85 = 557.79/x
  3. Step 3: Cross multiply
    686.31x = 1,027.85 × 557.79
  4. Step 4: Simplify right side
    686.31x = 573,321.66
  5. Step 5: Solve for x
    x = 573,321.66/686.31
  6. Step 6: Final answer
    x = 835.37

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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.