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Finding the Fourth Proportional to 206.43, 308.97 and 129.21

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Solution

The fourth proportional to 206.43, 308.97 and 129.21 is: 193.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.43 : 308.97 = 129.21 : x
  2. Step 2: Convert to fraction form
    206.43/308.97 = 129.21/x
  3. Step 3: Cross multiply
    206.43x = 308.97 × 129.21
  4. Step 4: Simplify right side
    206.43x = 39,922.01
  5. Step 5: Solve for x
    x = 39,922.01/206.43
  6. Step 6: Final answer
    x = 193.39

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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.