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Finding the Fourth Proportional to 408.20, 611.66 and 315.88

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Solution

The fourth proportional to 408.20, 611.66 and 315.88 is: 473.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.20 : 611.66 = 315.88 : x
  2. Step 2: Convert to fraction form
    408.20/611.66 = 315.88/x
  3. Step 3: Cross multiply
    408.20x = 611.66 × 315.88
  4. Step 4: Simplify right side
    408.20x = 193,211.16
  5. Step 5: Solve for x
    x = 193,211.16/408.20
  6. Step 6: Final answer
    x = 473.32

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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.