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Finding the Fourth Proportional to 680.39, 938.87 and 385.65

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Solution

The fourth proportional to 680.39, 938.87 and 385.65 is: 532.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.39 : 938.87 = 385.65 : x
  2. Step 2: Convert to fraction form
    680.39/938.87 = 385.65/x
  3. Step 3: Cross multiply
    680.39x = 938.87 × 385.65
  4. Step 4: Simplify right side
    680.39x = 362,073.29
  5. Step 5: Solve for x
    x = 362,073.29/680.39
  6. Step 6: Final answer
    x = 532.16

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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.