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Finding the Fourth Proportional to 120.27, 180.20 and 85.96

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Solution

The fourth proportional to 120.27, 180.20 and 85.96 is: 128.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.27 : 180.20 = 85.96 : x
  2. Step 2: Convert to fraction form
    120.27/180.20 = 85.96/x
  3. Step 3: Cross multiply
    120.27x = 180.20 × 85.96
  4. Step 4: Simplify right side
    120.27x = 15,488.66
  5. Step 5: Solve for x
    x = 15,488.66/120.27
  6. Step 6: Final answer
    x = 128.78

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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.