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Finding the Fourth Proportional to 668.20, 921.78 and 447.16

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Solution

The fourth proportional to 668.20, 921.78 and 447.16 is: 616.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.20 : 921.78 = 447.16 : x
  2. Step 2: Convert to fraction form
    668.20/921.78 = 447.16/x
  3. Step 3: Cross multiply
    668.20x = 921.78 × 447.16
  4. Step 4: Simplify right side
    668.20x = 412,183.14
  5. Step 5: Solve for x
    x = 412,183.14/668.20
  6. Step 6: Final answer
    x = 616.86

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.