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Finding the Fourth Proportional to 408.38, 611.42 and 253.85

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Solution

The fourth proportional to 408.38, 611.42 and 253.85 is: 380.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.38 : 611.42 = 253.85 : x
  2. Step 2: Convert to fraction form
    408.38/611.42 = 253.85/x
  3. Step 3: Cross multiply
    408.38x = 611.42 × 253.85
  4. Step 4: Simplify right side
    408.38x = 155,204.64
  5. Step 5: Solve for x
    x = 155,204.64/408.38
  6. Step 6: Final answer
    x = 380.05

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.