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Finding the Fourth Proportional to 680.59, 939.09 and 400.87

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Solution

The fourth proportional to 680.59, 939.09 and 400.87 is: 553.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.59 : 939.09 = 400.87 : x
  2. Step 2: Convert to fraction form
    680.59/939.09 = 400.87/x
  3. Step 3: Cross multiply
    680.59x = 939.09 × 400.87
  4. Step 4: Simplify right side
    680.59x = 376,453.01
  5. Step 5: Solve for x
    x = 376,453.01/680.59
  6. Step 6: Final answer
    x = 553.13

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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.