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Finding the Fourth Proportional to 638.46, 880.65 and 389.64

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Solution

The fourth proportional to 638.46, 880.65 and 389.64 is: 537.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.46 : 880.65 = 389.64 : x
  2. Step 2: Convert to fraction form
    638.46/880.65 = 389.64/x
  3. Step 3: Cross multiply
    638.46x = 880.65 × 389.64
  4. Step 4: Simplify right side
    638.46x = 343,136.47
  5. Step 5: Solve for x
    x = 343,136.47/638.46
  6. Step 6: Final answer
    x = 537.44

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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.