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Finding the Fourth Proportional to 138.62, 191.24 and 79.61

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Solution

The fourth proportional to 138.62, 191.24 and 79.61 is: 109.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.62 : 191.24 = 79.61 : x
  2. Step 2: Convert to fraction form
    138.62/191.24 = 79.61/x
  3. Step 3: Cross multiply
    138.62x = 191.24 × 79.61
  4. Step 4: Simplify right side
    138.62x = 15,223.26
  5. Step 5: Solve for x
    x = 15,223.26/138.62
  6. Step 6: Final answer
    x = 109.82

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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.