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Finding the Fourth Proportional to 5.25, 7.87 and 3.91

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Solution

The fourth proportional to 5.25, 7.87 and 3.91 is: 5.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    5.25 : 7.87 = 3.91 : x
  2. Step 2: Convert to fraction form
    5.25/7.87 = 3.91/x
  3. Step 3: Cross multiply
    5.25x = 7.87 × 3.91
  4. Step 4: Simplify right side
    5.25x = 30.73
  5. Step 5: Solve for x
    x = 30.73/5.25
  6. Step 6: Final answer
    x = 5.86

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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.