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Finding the Fourth Proportional to 680.57, 939.09 and 400.85

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Solution

The fourth proportional to 680.57, 939.09 and 400.85 is: 553.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.57 : 939.09 = 400.85 : x
  2. Step 2: Convert to fraction form
    680.57/939.09 = 400.85/x
  3. Step 3: Cross multiply
    680.57x = 939.09 × 400.85
  4. Step 4: Simplify right side
    680.57x = 376,434.23
  5. Step 5: Solve for x
    x = 376,434.23/680.57
  6. Step 6: Final answer
    x = 553.12

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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.