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Finding the Fourth Proportional to 13.87, 20.68 and 12.15

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Solution

The fourth proportional to 13.87, 20.68 and 12.15 is: 18.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.87 : 20.68 = 12.15 : x
  2. Step 2: Convert to fraction form
    13.87/20.68 = 12.15/x
  3. Step 3: Cross multiply
    13.87x = 20.68 × 12.15
  4. Step 4: Simplify right side
    13.87x = 251.27
  5. Step 5: Solve for x
    x = 251.27/13.87
  6. Step 6: Final answer
    x = 18.11

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.