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Finding the Fourth Proportional to 680.45, 938.81 and 400.70

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Solution

The fourth proportional to 680.45, 938.81 and 400.70 is: 552.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.45 : 938.81 = 400.70 : x
  2. Step 2: Convert to fraction form
    680.45/938.81 = 400.70/x
  3. Step 3: Cross multiply
    680.45x = 938.81 × 400.70
  4. Step 4: Simplify right side
    680.45x = 376,184.52
  5. Step 5: Solve for x
    x = 376,184.52/680.45
  6. Step 6: Final answer
    x = 552.85

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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.