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Finding the Fourth Proportional to 680.87, 1,021.34 and 408.71

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Solution

The fourth proportional to 680.87, 1,021.34 and 408.71 is: 613.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.87 : 1,021.34 = 408.71 : x
  2. Step 2: Convert to fraction form
    680.87/1,021.34 = 408.71/x
  3. Step 3: Cross multiply
    680.87x = 1,021.34 × 408.71
  4. Step 4: Simplify right side
    680.87x = 417,435.45
  5. Step 5: Solve for x
    x = 417,435.45/680.87
  6. Step 6: Final answer
    x = 613.09

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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.