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Finding the Fourth Proportional to 638.20, 880.68 and 389.44

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Solution

The fourth proportional to 638.20, 880.68 and 389.44 is: 537.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.20 : 880.68 = 389.44 : x
  2. Step 2: Convert to fraction form
    638.20/880.68 = 389.44/x
  3. Step 3: Cross multiply
    638.20x = 880.68 × 389.44
  4. Step 4: Simplify right side
    638.20x = 342,972.02
  5. Step 5: Solve for x
    x = 342,972.02/638.20
  6. Step 6: Final answer
    x = 537.41

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.