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Finding the Fourth Proportional to 398.95, 550.53 and 221.91

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Solution

The fourth proportional to 398.95, 550.53 and 221.91 is: 306.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.95 : 550.53 = 221.91 : x
  2. Step 2: Convert to fraction form
    398.95/550.53 = 221.91/x
  3. Step 3: Cross multiply
    398.95x = 550.53 × 221.91
  4. Step 4: Simplify right side
    398.95x = 122,168.11
  5. Step 5: Solve for x
    x = 122,168.11/398.95
  6. Step 6: Final answer
    x = 306.22

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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.