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Finding the Third Proportional to 20.81 and 39.66

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Solution

The third proportional to 20.81 and 39.66 is: 75.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.81 : 39.66 = 39.66 : x
  2. Step 2: Convert to fraction form
    20.81/39.66 = 39.66/x
  3. Step 3: Cross multiply
    20.81x = 39.66 × 39.66
  4. Step 4: Simplify right side
    20.81x = 1,572.62
  5. Step 5: Solve for x
    x = 1,572.62/20.81
  6. Step 6: Final answer
    x = 75.56

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Why These Related Problems?

These problems maintain the same ratio (1.91) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.