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Finding the Third Proportional to 81.50 and 108.75

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Solution

The third proportional to 81.50 and 108.75 is: 145.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.50 : 108.75 = 108.75 : x
  2. Step 2: Convert to fraction form
    81.50/108.75 = 108.75/x
  3. Step 3: Cross multiply
    81.50x = 108.75 × 108.75
  4. Step 4: Simplify right side
    81.50x = 11,826.56
  5. Step 5: Solve for x
    x = 11,826.56/81.50
  6. Step 6: Final answer
    x = 145.11

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Why These Related Problems?

These problems maintain the same ratio (1.33) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.