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Finding the Fourth Proportional to 638.21, 880.46 and 389.47

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Solution

The fourth proportional to 638.21, 880.46 and 389.47 is: 537.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.21 : 880.46 = 389.47 : x
  2. Step 2: Convert to fraction form
    638.21/880.46 = 389.47/x
  3. Step 3: Cross multiply
    638.21x = 880.46 × 389.47
  4. Step 4: Simplify right side
    638.21x = 342,912.76
  5. Step 5: Solve for x
    x = 342,912.76/638.21
  6. Step 6: Final answer
    x = 537.30

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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.