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Finding the Fourth Proportional to 221.78, 331.13 and 199.91

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Solution

The fourth proportional to 221.78, 331.13 and 199.91 is: 298.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.78 : 331.13 = 199.91 : x
  2. Step 2: Convert to fraction form
    221.78/331.13 = 199.91/x
  3. Step 3: Cross multiply
    221.78x = 331.13 × 199.91
  4. Step 4: Simplify right side
    221.78x = 66,193.54
  5. Step 5: Solve for x
    x = 66,193.54/221.78
  6. Step 6: Final answer
    x = 298.47

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.