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Finding the Fourth Proportional to 13.54, 20.31 and 3.91

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Solution

The fourth proportional to 13.54, 20.31 and 3.91 is: 5.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.54 : 20.31 = 3.91 : x
  2. Step 2: Convert to fraction form
    13.54/20.31 = 3.91/x
  3. Step 3: Cross multiply
    13.54x = 20.31 × 3.91
  4. Step 4: Simplify right side
    13.54x = 79.48
  5. Step 5: Solve for x
    x = 79.48/13.54
  6. Step 6: Final answer
    x = 5.87

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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.