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Finding the Fourth Proportional to 80.15, 109.92 and 77.82

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Solution

The fourth proportional to 80.15, 109.92 and 77.82 is: 106.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.15 : 109.92 = 77.82 : x
  2. Step 2: Convert to fraction form
    80.15/109.92 = 77.82/x
  3. Step 3: Cross multiply
    80.15x = 109.92 × 77.82
  4. Step 4: Simplify right side
    80.15x = 8,553.97
  5. Step 5: Solve for x
    x = 8,553.97/80.15
  6. Step 6: Final answer
    x = 106.73

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.