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Finding the Third Proportional to 9.91 and 21.09

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Solution

The third proportional to 9.91 and 21.09 is: 44.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.91 : 21.09 = 21.09 : x
  2. Step 2: Convert to fraction form
    9.91/21.09 = 21.09/x
  3. Step 3: Cross multiply
    9.91x = 21.09 × 21.09
  4. Step 4: Simplify right side
    9.91x = 444.95
  5. Step 5: Solve for x
    x = 444.95/9.91
  6. Step 6: Final answer
    x = 44.88

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Why These Related Problems?

These problems maintain the same ratio (2.13) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.