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Finding the Fourth Proportional to 638.68, 957.84 and 205.78

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Solution

The fourth proportional to 638.68, 957.84 and 205.78 is: 308.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.68 : 957.84 = 205.78 : x
  2. Step 2: Convert to fraction form
    638.68/957.84 = 205.78/x
  3. Step 3: Cross multiply
    638.68x = 957.84 × 205.78
  4. Step 4: Simplify right side
    638.68x = 197,104.32
  5. Step 5: Solve for x
    x = 197,104.32/638.68
  6. Step 6: Final answer
    x = 308.61

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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.