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Finding the Third Proportional to 81.75 and 129.38

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Solution

The third proportional to 81.75 and 129.38 is: 204.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.75 : 129.38 = 129.38 : x
  2. Step 2: Convert to fraction form
    81.75/129.38 = 129.38/x
  3. Step 3: Cross multiply
    81.75x = 129.38 × 129.38
  4. Step 4: Simplify right side
    81.75x = 16,737.89
  5. Step 5: Solve for x
    x = 16,737.89/81.75
  6. Step 6: Final answer
    x = 204.74

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Why These Related Problems?

These problems maintain the same ratio (1.58) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.