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Finding the Fourth Proportional to 80.60, 120.66 and 72.85

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Solution

The fourth proportional to 80.60, 120.66 and 72.85 is: 109.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.60 : 120.66 = 72.85 : x
  2. Step 2: Convert to fraction form
    80.60/120.66 = 72.85/x
  3. Step 3: Cross multiply
    80.60x = 120.66 × 72.85
  4. Step 4: Simplify right side
    80.60x = 8,790.08
  5. Step 5: Solve for x
    x = 8,790.08/80.60
  6. Step 6: Final answer
    x = 109.06

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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.