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Finding the Fourth Proportional to 86.29, 118.80 and 81.73

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Solution

The fourth proportional to 86.29, 118.80 and 81.73 is: 112.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.29 : 118.80 = 81.73 : x
  2. Step 2: Convert to fraction form
    86.29/118.80 = 81.73/x
  3. Step 3: Cross multiply
    86.29x = 118.80 × 81.73
  4. Step 4: Simplify right side
    86.29x = 9,709.52
  5. Step 5: Solve for x
    x = 9,709.52/86.29
  6. Step 6: Final answer
    x = 112.52

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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.