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Finding the Third Proportional to 12.87 and 19.72

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Solution

The third proportional to 12.87 and 19.72 is: 30.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.87 : 19.72 = 19.72 : x
  2. Step 2: Convert to fraction form
    12.87/19.72 = 19.72/x
  3. Step 3: Cross multiply
    12.87x = 19.72 × 19.72
  4. Step 4: Simplify right side
    12.87x = 388.98
  5. Step 5: Solve for x
    x = 388.98/12.87
  6. Step 6: Final answer
    x = 30.23

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Why These Related Problems?

These problems maintain the same ratio (1.53) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.