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Finding the Fourth Proportional to 680.21, 938.69 and 385.47

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Solution

The fourth proportional to 680.21, 938.69 and 385.47 is: 531.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.21 : 938.69 = 385.47 : x
  2. Step 2: Convert to fraction form
    680.21/938.69 = 385.47/x
  3. Step 3: Cross multiply
    680.21x = 938.69 × 385.47
  4. Step 4: Simplify right side
    680.21x = 361,834.91
  5. Step 5: Solve for x
    x = 361,834.91/680.21
  6. Step 6: Final answer
    x = 531.95

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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.