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Finding the Fourth Proportional to 398.64, 550.09 and 221.62

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Solution

The fourth proportional to 398.64, 550.09 and 221.62 is: 305.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.64 : 550.09 = 221.62 : x
  2. Step 2: Convert to fraction form
    398.64/550.09 = 221.62/x
  3. Step 3: Cross multiply
    398.64x = 550.09 × 221.62
  4. Step 4: Simplify right side
    398.64x = 121,910.95
  5. Step 5: Solve for x
    x = 121,910.95/398.64
  6. Step 6: Final answer
    x = 305.82

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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.