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Finding the Fourth Proportional to 11.21, 16.79 and 7.82

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Solution

The fourth proportional to 11.21, 16.79 and 7.82 is: 11.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    11.21 : 16.79 = 7.82 : x
  2. Step 2: Convert to fraction form
    11.21/16.79 = 7.82/x
  3. Step 3: Cross multiply
    11.21x = 16.79 × 7.82
  4. Step 4: Simplify right side
    11.21x = 131.21
  5. Step 5: Solve for x
    x = 131.21/11.21
  6. Step 6: Final answer
    x = 11.71

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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.