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Finding the Fourth Proportional to 83.15, 124.61 and 80.65

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Solution

The fourth proportional to 83.15, 124.61 and 80.65 is: 120.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.15 : 124.61 = 80.65 : x
  2. Step 2: Convert to fraction form
    83.15/124.61 = 80.65/x
  3. Step 3: Cross multiply
    83.15x = 124.61 × 80.65
  4. Step 4: Simplify right side
    83.15x = 10,049.53
  5. Step 5: Solve for x
    x = 10,049.53/83.15
  6. Step 6: Final answer
    x = 120.86

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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.