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Finding the Fourth Proportional to 85.09, 118.03 and 81.85

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Solution

The fourth proportional to 85.09, 118.03 and 81.85 is: 113.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.09 : 118.03 = 81.85 : x
  2. Step 2: Convert to fraction form
    85.09/118.03 = 81.85/x
  3. Step 3: Cross multiply
    85.09x = 118.03 × 81.85
  4. Step 4: Simplify right side
    85.09x = 9,660.76
  5. Step 5: Solve for x
    x = 9,660.76/85.09
  6. Step 6: Final answer
    x = 113.54

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.