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Finding the Fourth Proportional to 80.91, 120.75 and 68.71

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Solution

The fourth proportional to 80.91, 120.75 and 68.71 is: 102.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.91 : 120.75 = 68.71 : x
  2. Step 2: Convert to fraction form
    80.91/120.75 = 68.71/x
  3. Step 3: Cross multiply
    80.91x = 120.75 × 68.71
  4. Step 4: Simplify right side
    80.91x = 8,296.73
  5. Step 5: Solve for x
    x = 8,296.73/80.91
  6. Step 6: Final answer
    x = 102.54

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.