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Finding the Fourth Proportional to 686.17, 1,027.78 and 455.17

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Solution

The fourth proportional to 686.17, 1,027.78 and 455.17 is: 681.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.17 : 1,027.78 = 455.17 : x
  2. Step 2: Convert to fraction form
    686.17/1,027.78 = 455.17/x
  3. Step 3: Cross multiply
    686.17x = 1,027.78 × 455.17
  4. Step 4: Simplify right side
    686.17x = 467,814.62
  5. Step 5: Solve for x
    x = 467,814.62/686.17
  6. Step 6: Final answer
    x = 681.78

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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.