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Finding the Fourth Proportional to 81.91, 113.02 and 49.15

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Solution

The fourth proportional to 81.91, 113.02 and 49.15 is: 67.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.91 : 113.02 = 49.15 : x
  2. Step 2: Convert to fraction form
    81.91/113.02 = 49.15/x
  3. Step 3: Cross multiply
    81.91x = 113.02 × 49.15
  4. Step 4: Simplify right side
    81.91x = 5,554.93
  5. Step 5: Solve for x
    x = 5,554.93/81.91
  6. Step 6: Final answer
    x = 67.82

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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.