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Finding the Fourth Proportional to 221.12, 331.61 and 99.49

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Solution

The fourth proportional to 221.12, 331.61 and 99.49 is: 149.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.12 : 331.61 = 99.49 : x
  2. Step 2: Convert to fraction form
    221.12/331.61 = 99.49/x
  3. Step 3: Cross multiply
    221.12x = 331.61 × 99.49
  4. Step 4: Simplify right side
    221.12x = 32,991.88
  5. Step 5: Solve for x
    x = 32,991.88/221.12
  6. Step 6: Final answer
    x = 149.20

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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.