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Finding the Fourth Proportional to 221.20, 305.31 and 206.62

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Solution

The fourth proportional to 221.20, 305.31 and 206.62 is: 285.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.20 : 305.31 = 206.62 : x
  2. Step 2: Convert to fraction form
    221.20/305.31 = 206.62/x
  3. Step 3: Cross multiply
    221.20x = 305.31 × 206.62
  4. Step 4: Simplify right side
    221.20x = 63,083.15
  5. Step 5: Solve for x
    x = 63,083.15/221.20
  6. Step 6: Final answer
    x = 285.19

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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.