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Finding the Fourth Proportional to 686.18, 1,029.26 and 321.22

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Solution

The fourth proportional to 686.18, 1,029.26 and 321.22 is: 481.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.18 : 1,029.26 = 321.22 : x
  2. Step 2: Convert to fraction form
    686.18/1,029.26 = 321.22/x
  3. Step 3: Cross multiply
    686.18x = 1,029.26 × 321.22
  4. Step 4: Simplify right side
    686.18x = 330,619.70
  5. Step 5: Solve for x
    x = 330,619.70/686.18
  6. Step 6: Final answer
    x = 481.83

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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.