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Finding the Third Proportional to 9.90 and 21.14

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Solution

The third proportional to 9.90 and 21.14 is: 45.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.90 : 21.14 = 21.14 : x
  2. Step 2: Convert to fraction form
    9.90/21.14 = 21.14/x
  3. Step 3: Cross multiply
    9.90x = 21.14 × 21.14
  4. Step 4: Simplify right side
    9.90x = 446.92
  5. Step 5: Solve for x
    x = 446.92/9.90
  6. Step 6: Final answer
    x = 45.13

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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.