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Finding the Fourth Proportional to 638.11, 957.07 and 205.21

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Solution

The fourth proportional to 638.11, 957.07 and 205.21 is: 307.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.11 : 957.07 = 205.21 : x
  2. Step 2: Convert to fraction form
    638.11/957.07 = 205.21/x
  3. Step 3: Cross multiply
    638.11x = 957.07 × 205.21
  4. Step 4: Simplify right side
    638.11x = 196,400.33
  5. Step 5: Solve for x
    x = 196,400.33/638.11
  6. Step 6: Final answer
    x = 307.78

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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.