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Finding the Fourth Proportional to 87.94, 120.71 and 84.18

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Solution

The fourth proportional to 87.94, 120.71 and 84.18 is: 115.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.94 : 120.71 = 84.18 : x
  2. Step 2: Convert to fraction form
    87.94/120.71 = 84.18/x
  3. Step 3: Cross multiply
    87.94x = 120.71 × 84.18
  4. Step 4: Simplify right side
    87.94x = 10,161.22
  5. Step 5: Solve for x
    x = 10,161.22/87.94
  6. Step 6: Final answer
    x = 115.55

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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.