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Finding the Third Proportional to 3.31 and 7.21

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Solution

The third proportional to 3.31 and 7.21 is: 15.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.31 : 7.21 = 7.21 : x
  2. Step 2: Convert to fraction form
    3.31/7.21 = 7.21/x
  3. Step 3: Cross multiply
    3.31x = 7.21 × 7.21
  4. Step 4: Simplify right side
    3.31x = 51.93
  5. Step 5: Solve for x
    x = 51.93/3.31
  6. Step 6: Final answer
    x = 15.71

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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.