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Finding the Fourth Proportional to 398.95, 550.52 and 221.89

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Solution

The fourth proportional to 398.95, 550.52 and 221.89 is: 306.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.95 : 550.52 = 221.89 : x
  2. Step 2: Convert to fraction form
    398.95/550.52 = 221.89/x
  3. Step 3: Cross multiply
    398.95x = 550.52 × 221.89
  4. Step 4: Simplify right side
    398.95x = 122,154.89
  5. Step 5: Solve for x
    x = 122,154.89/398.95
  6. Step 6: Final answer
    x = 306.19

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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.