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Finding the Fourth Proportional to 408.45, 611.90 and 321.57

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Solution

The fourth proportional to 408.45, 611.90 and 321.57 is: 481.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.45 : 611.90 = 321.57 : x
  2. Step 2: Convert to fraction form
    408.45/611.90 = 321.57/x
  3. Step 3: Cross multiply
    408.45x = 611.90 × 321.57
  4. Step 4: Simplify right side
    408.45x = 196,767.08
  5. Step 5: Solve for x
    x = 196,767.08/408.45
  6. Step 6: Final answer
    x = 481.74

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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.