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Finding the Fourth Proportional to 20.20, 30.31 and 12.19

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Solution

The fourth proportional to 20.20, 30.31 and 12.19 is: 18.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.20 : 30.31 = 12.19 : x
  2. Step 2: Convert to fraction form
    20.20/30.31 = 12.19/x
  3. Step 3: Cross multiply
    20.20x = 30.31 × 12.19
  4. Step 4: Simplify right side
    20.20x = 369.48
  5. Step 5: Solve for x
    x = 369.48/20.20
  6. Step 6: Final answer
    x = 18.29

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.