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Finding the Third Proportional to 12.81 and 19.81

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Solution

The third proportional to 12.81 and 19.81 is: 30.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.81 : 19.81 = 19.81 : x
  2. Step 2: Convert to fraction form
    12.81/19.81 = 19.81/x
  3. Step 3: Cross multiply
    12.81x = 19.81 × 19.81
  4. Step 4: Simplify right side
    12.81x = 392.54
  5. Step 5: Solve for x
    x = 392.54/12.81
  6. Step 6: Final answer
    x = 30.64

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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.