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Finding the Fourth Proportional to 638.32, 881 and 389.64

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Solution

The fourth proportional to 638.32, 881 and 389.64 is: 537.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.32 : 881 = 389.64 : x
  2. Step 2: Convert to fraction form
    638.32/881 = 389.64/x
  3. Step 3: Cross multiply
    638.32x = 881 × 389.64
  4. Step 4: Simplify right side
    638.32x = 343,272.84
  5. Step 5: Solve for x
    x = 343,272.84/638.32
  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.