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Finding the Fourth Proportional to 81.75, 122.61 and 52.86

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Solution

The fourth proportional to 81.75, 122.61 and 52.86 is: 79.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.75 : 122.61 = 52.86 : x
  2. Step 2: Convert to fraction form
    81.75/122.61 = 52.86/x
  3. Step 3: Cross multiply
    81.75x = 122.61 × 52.86
  4. Step 4: Simplify right side
    81.75x = 6,481.82
  5. Step 5: Solve for x
    x = 6,481.82/81.75
  6. Step 6: Final answer
    x = 79.28

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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.