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Finding the Fourth Proportional to 221.03, 305 and 122.78

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Solution

The fourth proportional to 221.03, 305 and 122.78 is: 169.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.03 : 305 = 122.78 : x
  2. Step 2: Convert to fraction form
    221.03/305 = 122.78/x
  3. Step 3: Cross multiply
    221.03x = 305 × 122.78
  4. Step 4: Simplify right side
    221.03x = 37,447.90
  5. Step 5: Solve for x
    x = 37,447.90/221.03
  6. Step 6: Final answer
    x = 169.42

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.