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Finding the Fourth Proportional to 12.86, 19.31 and 10.87

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Solution

The fourth proportional to 12.86, 19.31 and 10.87 is: 16.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.86 : 19.31 = 10.87 : x
  2. Step 2: Convert to fraction form
    12.86/19.31 = 10.87/x
  3. Step 3: Cross multiply
    12.86x = 19.31 × 10.87
  4. Step 4: Simplify right side
    12.86x = 209.80
  5. Step 5: Solve for x
    x = 209.80/12.86
  6. Step 6: Final answer
    x = 16.32

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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.