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Finding the Fourth Proportional to 129.25, 178.31 and 82.61

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Solution

The fourth proportional to 129.25, 178.31 and 82.61 is: 113.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.25 : 178.31 = 82.61 : x
  2. Step 2: Convert to fraction form
    129.25/178.31 = 82.61/x
  3. Step 3: Cross multiply
    129.25x = 178.31 × 82.61
  4. Step 4: Simplify right side
    129.25x = 14,730.19
  5. Step 5: Solve for x
    x = 14,730.19/129.25
  6. Step 6: Final answer
    x = 113.97

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.