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Finding the Fourth Proportional to 686.10, 1,029.15 and 321.24

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Solution

The fourth proportional to 686.10, 1,029.15 and 321.24 is: 481.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.10 : 1,029.15 = 321.24 : x
  2. Step 2: Convert to fraction form
    686.10/1,029.15 = 321.24/x
  3. Step 3: Cross multiply
    686.10x = 1,029.15 × 321.24
  4. Step 4: Simplify right side
    686.10x = 330,604.15
  5. Step 5: Solve for x
    x = 330,604.15/686.10
  6. Step 6: Final answer
    x = 481.86

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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.