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Finding the Fourth Proportional to 10.86, 15 and 8.12

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Solution

The fourth proportional to 10.86, 15 and 8.12 is: 11.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    10.86 : 15 = 8.12 : x
  2. Step 2: Convert to fraction form
    10.86/15 = 8.12/x
  3. Step 3: Cross multiply
    10.86x = 15 × 8.12
  4. Step 4: Simplify right side
    10.86x = 121.73
  5. Step 5: Solve for x
    x = 121.73/10.86
  6. Step 6: Final answer
    x = 11.21

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.