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Finding the Third Proportional to 15,820 and 21,311

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Solution

The third proportional to 15,820 and 21,311 is: 28,707.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    15,820 : 21,311 = 21,311 : x
  2. Step 2: Convert to fraction form
    15,820/21,311 = 21,311/x
  3. Step 3: Cross multiply
    15,820x = 21,311 × 21,311
  4. Step 4: Simplify right side
    15,820x = 454,158,721
  5. Step 5: Solve for x
    x = 454,158,721/15,820
  6. Step 6: Final answer
    x = 28,707.88

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Why These Related Problems?

These problems maintain the same ratio (1.35) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.