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Finding the Fourth Proportional to 203.58, 305.42 and 81.86

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Solution

The fourth proportional to 203.58, 305.42 and 81.86 is: 122.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    203.58 : 305.42 = 81.86 : x
  2. Step 2: Convert to fraction form
    203.58/305.42 = 81.86/x
  3. Step 3: Cross multiply
    203.58x = 305.42 × 81.86
  4. Step 4: Simplify right side
    203.58x = 25,001.68
  5. Step 5: Solve for x
    x = 25,001.68/203.58
  6. Step 6: Final answer
    x = 122.81

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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.