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Finding the Fourth Proportional to 638.78, 958.19 and 205.88

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Solution

The fourth proportional to 638.78, 958.19 and 205.88 is: 308.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.78 : 958.19 = 205.88 : x
  2. Step 2: Convert to fraction form
    638.78/958.19 = 205.88/x
  3. Step 3: Cross multiply
    638.78x = 958.19 × 205.88
  4. Step 4: Simplify right side
    638.78x = 197,266.34
  5. Step 5: Solve for x
    x = 197,266.34/638.78
  6. Step 6: Final answer
    x = 308.82

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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.