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Finding the Third Proportional to 3.81 and 8.31

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Solution

The third proportional to 3.81 and 8.31 is: 18.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.81 : 8.31 = 8.31 : x
  2. Step 2: Convert to fraction form
    3.81/8.31 = 8.31/x
  3. Step 3: Cross multiply
    3.81x = 8.31 × 8.31
  4. Step 4: Simplify right side
    3.81x = 69.10
  5. Step 5: Solve for x
    x = 69.10/3.81
  6. Step 6: Final answer
    x = 18.12

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Why These Related Problems?

These problems maintain the same ratio (2.18) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.