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Finding the Fourth Proportional to 81.79, 122.70 and 27.69

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Solution

The fourth proportional to 81.79, 122.70 and 27.69 is: 41.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.79 : 122.70 = 27.69 : x
  2. Step 2: Convert to fraction form
    81.79/122.70 = 27.69/x
  3. Step 3: Cross multiply
    81.79x = 122.70 × 27.69
  4. Step 4: Simplify right side
    81.79x = 3,397.56
  5. Step 5: Solve for x
    x = 3,397.56/81.79
  6. Step 6: Final answer
    x = 41.54

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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.