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Finding the Fourth Proportional to 680.29, 938.79 and 385.56

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Solution

The fourth proportional to 680.29, 938.79 and 385.56 is: 532.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.29 : 938.79 = 385.56 : x
  2. Step 2: Convert to fraction form
    680.29/938.79 = 385.56/x
  3. Step 3: Cross multiply
    680.29x = 938.79 × 385.56
  4. Step 4: Simplify right side
    680.29x = 361,959.87
  5. Step 5: Solve for x
    x = 361,959.87/680.29
  6. Step 6: Final answer
    x = 532.07

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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.