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Finding the Fourth Proportional to 11.31, 15.60 and 7.86

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Solution

The fourth proportional to 11.31, 15.60 and 7.86 is: 10.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    11.31 : 15.60 = 7.86 : x
  2. Step 2: Convert to fraction form
    11.31/15.60 = 7.86/x
  3. Step 3: Cross multiply
    11.31x = 15.60 × 7.86
  4. Step 4: Simplify right side
    11.31x = 122.58
  5. Step 5: Solve for x
    x = 122.58/11.31
  6. Step 6: Final answer
    x = 10.84

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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.