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Finding the Fourth Proportional to 668.65, 1,000.38 and 408.61

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Solution

The fourth proportional to 668.65, 1,000.38 and 408.61 is: 611.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.65 : 1,000.38 = 408.61 : x
  2. Step 2: Convert to fraction form
    668.65/1,000.38 = 408.61/x
  3. Step 3: Cross multiply
    668.65x = 1,000.38 × 408.61
  4. Step 4: Simplify right side
    668.65x = 408,765.27
  5. Step 5: Solve for x
    x = 408,765.27/668.65
  6. Step 6: Final answer
    x = 611.33

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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.