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Finding the Third Proportional to 20.50 and 39.88

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Solution

The third proportional to 20.50 and 39.88 is: 77.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.50 : 39.88 = 39.88 : x
  2. Step 2: Convert to fraction form
    20.50/39.88 = 39.88/x
  3. Step 3: Cross multiply
    20.50x = 39.88 × 39.88
  4. Step 4: Simplify right side
    20.50x = 1,590.02
  5. Step 5: Solve for x
    x = 1,590.02/20.50
  6. Step 6: Final answer
    x = 77.56

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Why These Related Problems?

These problems maintain the same ratio (1.95) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.