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Finding the Fourth Proportional to 680.45, 1,020.17 and 217.96

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Solution

The fourth proportional to 680.45, 1,020.17 and 217.96 is: 326.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.45 : 1,020.17 = 217.96 : x
  2. Step 2: Convert to fraction form
    680.45/1,020.17 = 217.96/x
  3. Step 3: Cross multiply
    680.45x = 1,020.17 × 217.96
  4. Step 4: Simplify right side
    680.45x = 222,356.25
  5. Step 5: Solve for x
    x = 222,356.25/680.45
  6. Step 6: Final answer
    x = 326.78

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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.