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Finding the Fourth Proportional to 221.75, 331.79 and 138.39

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Solution

The fourth proportional to 221.75, 331.79 and 138.39 is: 207.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.75 : 331.79 = 138.39 : x
  2. Step 2: Convert to fraction form
    221.75/331.79 = 138.39/x
  3. Step 3: Cross multiply
    221.75x = 331.79 × 138.39
  4. Step 4: Simplify right side
    221.75x = 45,914.76
  5. Step 5: Solve for x
    x = 45,914.76/221.75
  6. Step 6: Final answer
    x = 207.06

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.