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Finding the Fourth Proportional to 20.15, 30.22 and 12.56

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Solution

The fourth proportional to 20.15, 30.22 and 12.56 is: 18.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.15 : 30.22 = 12.56 : x
  2. Step 2: Convert to fraction form
    20.15/30.22 = 12.56/x
  3. Step 3: Cross multiply
    20.15x = 30.22 × 12.56
  4. Step 4: Simplify right side
    20.15x = 379.35
  5. Step 5: Solve for x
    x = 379.35/20.15
  6. Step 6: Final answer
    x = 18.83

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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.