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Finding the Fourth Proportional to 668.43, 1,002.12 and 408.55

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Solution

The fourth proportional to 668.43, 1,002.12 and 408.55 is: 612.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.43 : 1,002.12 = 408.55 : x
  2. Step 2: Convert to fraction form
    668.43/1,002.12 = 408.55/x
  3. Step 3: Cross multiply
    668.43x = 1,002.12 × 408.55
  4. Step 4: Simplify right side
    668.43x = 409,414.64
  5. Step 5: Solve for x
    x = 409,414.64/668.43
  6. Step 6: Final answer
    x = 612.51

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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.