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Finding the Fourth Proportional to 20.82, 31.24 and 12.26

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Solution

The fourth proportional to 20.82, 31.24 and 12.26 is: 18.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.82 : 31.24 = 12.26 : x
  2. Step 2: Convert to fraction form
    20.82/31.24 = 12.26/x
  3. Step 3: Cross multiply
    20.82x = 31.24 × 12.26
  4. Step 4: Simplify right side
    20.82x = 383.10
  5. Step 5: Solve for x
    x = 383.10/20.82
  6. Step 6: Final answer
    x = 18.40

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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.