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Finding the Fourth Proportional to 80.92, 121.87 and 80.20

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Solution

The fourth proportional to 80.92, 121.87 and 80.20 is: 120.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.92 : 121.87 = 80.20 : x
  2. Step 2: Convert to fraction form
    80.92/121.87 = 80.20/x
  3. Step 3: Cross multiply
    80.92x = 121.87 × 80.20
  4. Step 4: Simplify right side
    80.92x = 9,773.97
  5. Step 5: Solve for x
    x = 9,773.97/80.92
  6. Step 6: Final answer
    x = 120.79

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.