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Finding the Fourth Proportional to 638.35, 880.85 and 389.73

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Solution

The fourth proportional to 638.35, 880.85 and 389.73 is: 537.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.35 : 880.85 = 389.73 : x
  2. Step 2: Convert to fraction form
    638.35/880.85 = 389.73/x
  3. Step 3: Cross multiply
    638.35x = 880.85 × 389.73
  4. Step 4: Simplify right side
    638.35x = 343,293.67
  5. Step 5: Solve for x
    x = 343,293.67/638.35
  6. Step 6: Final answer
    x = 537.78

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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.