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Finding the Fourth Proportional to 80.81, 111.61 and 67.17

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Solution

The fourth proportional to 80.81, 111.61 and 67.17 is: 92.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.81 : 111.61 = 67.17 : x
  2. Step 2: Convert to fraction form
    80.81/111.61 = 67.17/x
  3. Step 3: Cross multiply
    80.81x = 111.61 × 67.17
  4. Step 4: Simplify right side
    80.81x = 7,497.35
  5. Step 5: Solve for x
    x = 7,497.35/80.81
  6. Step 6: Final answer
    x = 92.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.