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Finding the Fourth Proportional to 81.27, 121.14 and 76.05

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Solution

The fourth proportional to 81.27, 121.14 and 76.05 is: 113.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.27 : 121.14 = 76.05 : x
  2. Step 2: Convert to fraction form
    81.27/121.14 = 76.05/x
  3. Step 3: Cross multiply
    81.27x = 121.14 × 76.05
  4. Step 4: Simplify right side
    81.27x = 9,212.70
  5. Step 5: Solve for x
    x = 9,212.70/81.27
  6. Step 6: Final answer
    x = 113.36

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.