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Finding the Third Proportional to 15,831 and 21,312

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Solution

The third proportional to 15,831 and 21,312 is: 28,690.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    15,831 : 21,312 = 21,312 : x
  2. Step 2: Convert to fraction form
    15,831/21,312 = 21,312/x
  3. Step 3: Cross multiply
    15,831x = 21,312 × 21,312
  4. Step 4: Simplify right side
    15,831x = 454,201,344
  5. Step 5: Solve for x
    x = 454,201,344/15,831
  6. Step 6: Final answer
    x = 28,690.63

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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.