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Finding the Fourth Proportional to 20.17, 30.21 and 15.09

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Solution

The fourth proportional to 20.17, 30.21 and 15.09 is: 22.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.17 : 30.21 = 15.09 : x
  2. Step 2: Convert to fraction form
    20.17/30.21 = 15.09/x
  3. Step 3: Cross multiply
    20.17x = 30.21 × 15.09
  4. Step 4: Simplify right side
    20.17x = 455.87
  5. Step 5: Solve for x
    x = 455.87/20.17
  6. Step 6: Final answer
    x = 22.61

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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.