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Finding the Third Proportional to 20.39 and 31.71

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Solution

The third proportional to 20.39 and 31.71 is: 49.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.39 : 31.71 = 31.71 : x
  2. Step 2: Convert to fraction form
    20.39/31.71 = 31.71/x
  3. Step 3: Cross multiply
    20.39x = 31.71 × 31.71
  4. Step 4: Simplify right side
    20.39x = 1,005.58
  5. Step 5: Solve for x
    x = 1,005.58/20.39
  6. Step 6: Final answer
    x = 49.32

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Why These Related Problems?

These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.