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Finding the Fourth Proportional to 686.87, 1,029.81 and 321.46

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Solution

The fourth proportional to 686.87, 1,029.81 and 321.46 is: 481.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.87 : 1,029.81 = 321.46 : x
  2. Step 2: Convert to fraction form
    686.87/1,029.81 = 321.46/x
  3. Step 3: Cross multiply
    686.87x = 1,029.81 × 321.46
  4. Step 4: Simplify right side
    686.87x = 331,042.72
  5. Step 5: Solve for x
    x = 331,042.72/686.87
  6. Step 6: Final answer
    x = 481.96

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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.