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Finding the Fourth Proportional to 87.88, 120.39 and 86.80

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Solution

The fourth proportional to 87.88, 120.39 and 86.80 is: 118.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.88 : 120.39 = 86.80 : x
  2. Step 2: Convert to fraction form
    87.88/120.39 = 86.80/x
  3. Step 3: Cross multiply
    87.88x = 120.39 × 86.80
  4. Step 4: Simplify right side
    87.88x = 10,449.85
  5. Step 5: Solve for x
    x = 10,449.85/87.88
  6. Step 6: Final answer
    x = 118.91

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.