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Finding the Fourth Proportional to 122.05, 168.39 and 87.09

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Solution

The fourth proportional to 122.05, 168.39 and 87.09 is: 120.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.05 : 168.39 = 87.09 : x
  2. Step 2: Convert to fraction form
    122.05/168.39 = 87.09/x
  3. Step 3: Cross multiply
    122.05x = 168.39 × 87.09
  4. Step 4: Simplify right side
    122.05x = 14,665.09
  5. Step 5: Solve for x
    x = 14,665.09/122.05
  6. Step 6: Final answer
    x = 120.16

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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.