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Finding the Fourth Proportional to 203.85, 305.81 and 82.21

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Solution

The fourth proportional to 203.85, 305.81 and 82.21 is: 123.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    203.85 : 305.81 = 82.21 : x
  2. Step 2: Convert to fraction form
    203.85/305.81 = 82.21/x
  3. Step 3: Cross multiply
    203.85x = 305.81 × 82.21
  4. Step 4: Simplify right side
    203.85x = 25,140.64
  5. Step 5: Solve for x
    x = 25,140.64/203.85
  6. Step 6: Final answer
    x = 123.33

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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.