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Finding the Fourth Proportional to 81.11, 120.76 and 79.97

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Solution

The fourth proportional to 81.11, 120.76 and 79.97 is: 119.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.11 : 120.76 = 79.97 : x
  2. Step 2: Convert to fraction form
    81.11/120.76 = 79.97/x
  3. Step 3: Cross multiply
    81.11x = 120.76 × 79.97
  4. Step 4: Simplify right side
    81.11x = 9,657.28
  5. Step 5: Solve for x
    x = 9,657.28/81.11
  6. Step 6: Final answer
    x = 119.06

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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.