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Finding the Fourth Proportional to 638.49, 957.70 and 205.61

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Solution

The fourth proportional to 638.49, 957.70 and 205.61 is: 308.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.49 : 957.70 = 205.61 : x
  2. Step 2: Convert to fraction form
    638.49/957.70 = 205.61/x
  3. Step 3: Cross multiply
    638.49x = 957.70 × 205.61
  4. Step 4: Simplify right side
    638.49x = 196,912.70
  5. Step 5: Solve for x
    x = 196,912.70/638.49
  6. Step 6: Final answer
    x = 308.40

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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.