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Finding the Fourth Proportional to 136.62, 204.95 and 81.87

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Solution

The fourth proportional to 136.62, 204.95 and 81.87 is: 122.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.62 : 204.95 = 81.87 : x
  2. Step 2: Convert to fraction form
    136.62/204.95 = 81.87/x
  3. Step 3: Cross multiply
    136.62x = 204.95 × 81.87
  4. Step 4: Simplify right side
    136.62x = 16,778.85
  5. Step 5: Solve for x
    x = 16,778.85/136.62
  6. Step 6: Final answer
    x = 122.81

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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.