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Finding the Fourth Proportional to 18.86, 28.31 and 10.85

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Solution

The fourth proportional to 18.86, 28.31 and 10.85 is: 16.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    18.86 : 28.31 = 10.85 : x
  2. Step 2: Convert to fraction form
    18.86/28.31 = 10.85/x
  3. Step 3: Cross multiply
    18.86x = 28.31 × 10.85
  4. Step 4: Simplify right side
    18.86x = 306.97
  5. Step 5: Solve for x
    x = 306.97/18.86
  6. Step 6: Final answer
    x = 16.28

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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.