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Finding the Fourth Proportional to 398.75, 550.27 and 221.71

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Solution

The fourth proportional to 398.75, 550.27 and 221.71 is: 305.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.75 : 550.27 = 221.71 : x
  2. Step 2: Convert to fraction form
    398.75/550.27 = 221.71/x
  3. Step 3: Cross multiply
    398.75x = 550.27 × 221.71
  4. Step 4: Simplify right side
    398.75x = 121,999.94
  5. Step 5: Solve for x
    x = 121,999.94/398.75
  6. Step 6: Final answer
    x = 305.96

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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.