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Finding the Third Proportional to 81 and 115

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Solution

The third proportional to 81 and 115 is: 163.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    81 : 115 = 115 : x
  2. Step 2: Convert to fraction form
    81/115 = 115/x
  3. Step 3: Cross multiply
    81x = 115 × 115
  4. Step 4: Simplify right side
    81x = 13,225
  5. Step 5: Solve for x
    x = 13,225/81
  6. Step 6: Final answer
    x = 163.27

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Why These Related Problems?

These problems maintain the same ratio (1.42) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.