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Finding the Third Proportional to 15,021 and 21,129

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Solution

The third proportional to 15,021 and 21,129 is: 29,720.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    15,021 : 21,129 = 21,129 : x
  2. Step 2: Convert to fraction form
    15,021/21,129 = 21,129/x
  3. Step 3: Cross multiply
    15,021x = 21,129 × 21,129
  4. Step 4: Simplify right side
    15,021x = 446,434,641
  5. Step 5: Solve for x
    x = 446,434,641/15,021
  6. Step 6: Final answer
    x = 29,720.70

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Why These Related Problems?

These problems maintain the same ratio (1.41) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.