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Finding the Third Proportional to 12.84 and 19.91

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Solution

The third proportional to 12.84 and 19.91 is: 30.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.84 : 19.91 = 19.91 : x
  2. Step 2: Convert to fraction form
    12.84/19.91 = 19.91/x
  3. Step 3: Cross multiply
    12.84x = 19.91 × 19.91
  4. Step 4: Simplify right side
    12.84x = 396.30
  5. Step 5: Solve for x
    x = 396.30/12.84
  6. Step 6: Final answer
    x = 30.86

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Why These Related Problems?

These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.