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Finding the Fourth Proportional to 399, 550.61 and 221.96

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Solution

The fourth proportional to 399, 550.61 and 221.96 is: 306.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    399 : 550.61 = 221.96 : x
  2. Step 2: Convert to fraction form
    399/550.61 = 221.96/x
  3. Step 3: Cross multiply
    399x = 550.61 × 221.96
  4. Step 4: Simplify right side
    399x = 122,214.77
  5. Step 5: Solve for x
    x = 122,214.77/399
  6. Step 6: Final answer
    x = 306.30

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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.