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Finding the Third Proportional to 3.09 and 6.90

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Solution

The third proportional to 3.09 and 6.90 is: 15.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.09 : 6.90 = 6.90 : x
  2. Step 2: Convert to fraction form
    3.09/6.90 = 6.90/x
  3. Step 3: Cross multiply
    3.09x = 6.90 × 6.90
  4. Step 4: Simplify right side
    3.09x = 47.56
  5. Step 5: Solve for x
    x = 47.56/3.09
  6. Step 6: Final answer
    x = 15.38

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Why These Related Problems?

These problems maintain the same ratio (2.23) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.