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Finding the Fourth Proportional to 203.59, 305.39 and 81.85

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Solution

The fourth proportional to 203.59, 305.39 and 81.85 is: 122.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    203.59 : 305.39 = 81.85 : x
  2. Step 2: Convert to fraction form
    203.59/305.39 = 81.85/x
  3. Step 3: Cross multiply
    203.59x = 305.39 × 81.85
  4. Step 4: Simplify right side
    203.59x = 24,996.17
  5. Step 5: Solve for x
    x = 24,996.17/203.59
  6. Step 6: Final answer
    x = 122.78

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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.