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Finding the Fourth Proportional to 87.11, 120.20 and 49.77

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Solution

The fourth proportional to 87.11, 120.20 and 49.77 is: 68.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.11 : 120.20 = 49.77 : x
  2. Step 2: Convert to fraction form
    87.11/120.20 = 49.77/x
  3. Step 3: Cross multiply
    87.11x = 120.20 × 49.77
  4. Step 4: Simplify right side
    87.11x = 5,982.35
  5. Step 5: Solve for x
    x = 5,982.35/87.11
  6. Step 6: Final answer
    x = 68.68

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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.