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Finding the Fourth Proportional to 638.69, 958.04 and 205.85

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Solution

The fourth proportional to 638.69, 958.04 and 205.85 is: 308.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.69 : 958.04 = 205.85 : x
  2. Step 2: Convert to fraction form
    638.69/958.04 = 205.85/x
  3. Step 3: Cross multiply
    638.69x = 958.04 × 205.85
  4. Step 4: Simplify right side
    638.69x = 197,215.44
  5. Step 5: Solve for x
    x = 197,215.44/638.69
  6. Step 6: Final answer
    x = 308.78

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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.