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Finding the Fourth Proportional to 638.49, 957.31 and 221.92

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Solution

The fourth proportional to 638.49, 957.31 and 221.92 is: 332.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.49 : 957.31 = 221.92 : x
  2. Step 2: Convert to fraction form
    638.49/957.31 = 221.92/x
  3. Step 3: Cross multiply
    638.49x = 957.31 × 221.92
  4. Step 4: Simplify right side
    638.49x = 212,440.34
  5. Step 5: Solve for x
    x = 212,440.34/638.49
  6. Step 6: Final answer
    x = 332.72

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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.