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Finding the Fourth Proportional to 8.20, 12.31 and 6.31

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Solution

The fourth proportional to 8.20, 12.31 and 6.31 is: 9.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.20 : 12.31 = 6.31 : x
  2. Step 2: Convert to fraction form
    8.20/12.31 = 6.31/x
  3. Step 3: Cross multiply
    8.20x = 12.31 × 6.31
  4. Step 4: Simplify right side
    8.20x = 77.68
  5. Step 5: Solve for x
    x = 77.68/8.20
  6. Step 6: Final answer
    x = 9.47

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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.