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Finding the Third Proportional to 12.78 and 28.09

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Solution

The third proportional to 12.78 and 28.09 is: 61.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.78 : 28.09 = 28.09 : x
  2. Step 2: Convert to fraction form
    12.78/28.09 = 28.09/x
  3. Step 3: Cross multiply
    12.78x = 28.09 × 28.09
  4. Step 4: Simplify right side
    12.78x = 789.26
  5. Step 5: Solve for x
    x = 789.26/12.78
  6. Step 6: Final answer
    x = 61.75

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Why These Related Problems?

These problems maintain the same ratio (2.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.