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Finding the Fourth Proportional to 221.72, 306.09 and 143.15

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Solution

The fourth proportional to 221.72, 306.09 and 143.15 is: 197.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.72 : 306.09 = 143.15 : x
  2. Step 2: Convert to fraction form
    221.72/306.09 = 143.15/x
  3. Step 3: Cross multiply
    221.72x = 306.09 × 143.15
  4. Step 4: Simplify right side
    221.72x = 43,816.78
  5. Step 5: Solve for x
    x = 43,816.78/221.72
  6. Step 6: Final answer
    x = 197.62

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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.