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Finding the Third Proportional to 3.90 and 8.71

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Solution

The third proportional to 3.90 and 8.71 is: 19.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    3.90 : 8.71 = 8.71 : x
  2. Step 2: Convert to fraction form
    3.90/8.71 = 8.71/x
  3. Step 3: Cross multiply
    3.90x = 8.71 × 8.71
  4. Step 4: Simplify right side
    3.90x = 75.86
  5. Step 5: Solve for x
    x = 75.86/3.90
  6. Step 6: Final answer
    x = 19.43

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Why These Related Problems?

These problems maintain the same ratio (2.23) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.