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Finding the Fourth Proportional to 668.74, 921.36 and 493.78

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Solution

The fourth proportional to 668.74, 921.36 and 493.78 is: 680.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.74 : 921.36 = 493.78 : x
  2. Step 2: Convert to fraction form
    668.74/921.36 = 493.78/x
  3. Step 3: Cross multiply
    668.74x = 921.36 × 493.78
  4. Step 4: Simplify right side
    668.74x = 454,949.14
  5. Step 5: Solve for x
    x = 454,949.14/668.74
  6. Step 6: Final answer
    x = 680.31

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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.