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Finding the Fourth Proportional to 81.06, 120.87 and 76.94

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Solution

The fourth proportional to 81.06, 120.87 and 76.94 is: 114.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.06 : 120.87 = 76.94 : x
  2. Step 2: Convert to fraction form
    81.06/120.87 = 76.94/x
  3. Step 3: Cross multiply
    81.06x = 120.87 × 76.94
  4. Step 4: Simplify right side
    81.06x = 9,299.59
  5. Step 5: Solve for x
    x = 9,299.59/81.06
  6. Step 6: Final answer
    x = 114.73

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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.