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Finding the Fourth Proportional to 80.71, 120.90 and 54.97

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Solution

The fourth proportional to 80.71, 120.90 and 54.97 is: 82.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.71 : 120.90 = 54.97 : x
  2. Step 2: Convert to fraction form
    80.71/120.90 = 54.97/x
  3. Step 3: Cross multiply
    80.71x = 120.90 × 54.97
  4. Step 4: Simplify right side
    80.71x = 6,645.78
  5. Step 5: Solve for x
    x = 6,645.78/80.71
  6. Step 6: Final answer
    x = 82.34

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.