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Finding the Fourth Proportional to 680.12, 1,020.17 and 217.90

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Solution

The fourth proportional to 680.12, 1,020.17 and 217.90 is: 326.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.12 : 1,020.17 = 217.90 : x
  2. Step 2: Convert to fraction form
    680.12/1,020.17 = 217.90/x
  3. Step 3: Cross multiply
    680.12x = 1,020.17 × 217.90
  4. Step 4: Simplify right side
    680.12x = 222,295.04
  5. Step 5: Solve for x
    x = 222,295.04/680.12
  6. Step 6: Final answer
    x = 326.85

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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.