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Finding the Fourth Proportional to 221.03, 331.90 and 129.80

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Solution

The fourth proportional to 221.03, 331.90 and 129.80 is: 194.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.03 : 331.90 = 129.80 : x
  2. Step 2: Convert to fraction form
    221.03/331.90 = 129.80/x
  3. Step 3: Cross multiply
    221.03x = 331.90 × 129.80
  4. Step 4: Simplify right side
    221.03x = 43,080.62
  5. Step 5: Solve for x
    x = 43,080.62/221.03
  6. Step 6: Final answer
    x = 194.91

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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.