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Finding the Fourth Proportional to 408.98, 613.80 and 311.78

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Solution

The fourth proportional to 408.98, 613.80 and 311.78 is: 467.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.98 : 613.80 = 311.78 : x
  2. Step 2: Convert to fraction form
    408.98/613.80 = 311.78/x
  3. Step 3: Cross multiply
    408.98x = 613.80 × 311.78
  4. Step 4: Simplify right side
    408.98x = 191,370.56
  5. Step 5: Solve for x
    x = 191,370.56/408.98
  6. Step 6: Final answer
    x = 467.92

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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.