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Finding the Fourth Proportional to 408.07, 611.90 and 261.79

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Solution

The fourth proportional to 408.07, 611.90 and 261.79 is: 392.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.07 : 611.90 = 261.79 : x
  2. Step 2: Convert to fraction form
    408.07/611.90 = 261.79/x
  3. Step 3: Cross multiply
    408.07x = 611.90 × 261.79
  4. Step 4: Simplify right side
    408.07x = 160,190.83
  5. Step 5: Solve for x
    x = 160,190.83/408.07
  6. Step 6: Final answer
    x = 392.55

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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.