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Finding the Fourth Proportional to 80.31, 120.26 and 72.61

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Solution

The fourth proportional to 80.31, 120.26 and 72.61 is: 108.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.31 : 120.26 = 72.61 : x
  2. Step 2: Convert to fraction form
    80.31/120.26 = 72.61/x
  3. Step 3: Cross multiply
    80.31x = 120.26 × 72.61
  4. Step 4: Simplify right side
    80.31x = 8,732.26
  5. Step 5: Solve for x
    x = 8,732.26/80.31
  6. Step 6: Final answer
    x = 108.74

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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.