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Finding the Fourth Proportional to 87.85, 131.79 and 80.12

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Solution

The fourth proportional to 87.85, 131.79 and 80.12 is: 120.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.85 : 131.79 = 80.12 : x
  2. Step 2: Convert to fraction form
    87.85/131.79 = 80.12/x
  3. Step 3: Cross multiply
    87.85x = 131.79 × 80.12
  4. Step 4: Simplify right side
    87.85x = 10,559.64
  5. Step 5: Solve for x
    x = 10,559.64/87.85
  6. Step 6: Final answer
    x = 120.20

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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.