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Finding the Fourth Proportional to 122.05, 182.87 and 85.90

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Solution

The fourth proportional to 122.05, 182.87 and 85.90 is: 128.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.05 : 182.87 = 85.90 : x
  2. Step 2: Convert to fraction form
    122.05/182.87 = 85.90/x
  3. Step 3: Cross multiply
    122.05x = 182.87 × 85.90
  4. Step 4: Simplify right side
    122.05x = 15,708.95
  5. Step 5: Solve for x
    x = 15,708.95/122.05
  6. Step 6: Final answer
    x = 128.71

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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.