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Finding the Third Proportional to 21.09 and 28.69

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Solution

The third proportional to 21.09 and 28.69 is: 39.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    21.09 : 28.69 = 28.69 : x
  2. Step 2: Convert to fraction form
    21.09/28.69 = 28.69/x
  3. Step 3: Cross multiply
    21.09x = 28.69 × 28.69
  4. Step 4: Simplify right side
    21.09x = 822.97
  5. Step 5: Solve for x
    x = 822.97/21.09
  6. Step 6: Final answer
    x = 39.02

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.