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Finding the Fourth Proportional to 81.23, 111.89 and 57.87

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Solution

The fourth proportional to 81.23, 111.89 and 57.87 is: 79.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.23 : 111.89 = 57.87 : x
  2. Step 2: Convert to fraction form
    81.23/111.89 = 57.87/x
  3. Step 3: Cross multiply
    81.23x = 111.89 × 57.87
  4. Step 4: Simplify right side
    81.23x = 6,474.78
  5. Step 5: Solve for x
    x = 6,474.78/81.23
  6. Step 6: Final answer
    x = 79.71

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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.