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Finding the Fourth Proportional to 221.04, 331.47 and 129.78

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Solution

The fourth proportional to 221.04, 331.47 and 129.78 is: 194.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.04 : 331.47 = 129.78 : x
  2. Step 2: Convert to fraction form
    221.04/331.47 = 129.78/x
  3. Step 3: Cross multiply
    221.04x = 331.47 × 129.78
  4. Step 4: Simplify right side
    221.04x = 43,018.18
  5. Step 5: Solve for x
    x = 43,018.18/221.04
  6. Step 6: Final answer
    x = 194.62

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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.