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Finding the Fourth Proportional to 638.48, 957.78 and 205.64

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Solution

The fourth proportional to 638.48, 957.78 and 205.64 is: 308.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.48 : 957.78 = 205.64 : x
  2. Step 2: Convert to fraction form
    638.48/957.78 = 205.64/x
  3. Step 3: Cross multiply
    638.48x = 957.78 × 205.64
  4. Step 4: Simplify right side
    638.48x = 196,957.88
  5. Step 5: Solve for x
    x = 196,957.88/638.48
  6. Step 6: Final answer
    x = 308.48

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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.