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Finding the Fourth Proportional to 103.86, 155.82 and 81.24

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Solution

The fourth proportional to 103.86, 155.82 and 81.24 is: 121.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.86 : 155.82 = 81.24 : x
  2. Step 2: Convert to fraction form
    103.86/155.82 = 81.24/x
  3. Step 3: Cross multiply
    103.86x = 155.82 × 81.24
  4. Step 4: Simplify right side
    103.86x = 12,658.82
  5. Step 5: Solve for x
    x = 12,658.82/103.86
  6. Step 6: Final answer
    x = 121.88

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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.