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Finding the Fourth Proportional to 638.43, 957.78 and 205.57

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Solution

The fourth proportional to 638.43, 957.78 and 205.57 is: 308.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.43 : 957.78 = 205.57 : x
  2. Step 2: Convert to fraction form
    638.43/957.78 = 205.57/x
  3. Step 3: Cross multiply
    638.43x = 957.78 × 205.57
  4. Step 4: Simplify right side
    638.43x = 196,890.83
  5. Step 5: Solve for x
    x = 196,890.83/638.43
  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.