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Finding the Fourth Proportional to 680.51, 939.09 and 385.78

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Solution

The fourth proportional to 680.51, 939.09 and 385.78 is: 532.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.51 : 939.09 = 385.78 : x
  2. Step 2: Convert to fraction form
    680.51/939.09 = 385.78/x
  3. Step 3: Cross multiply
    680.51x = 939.09 × 385.78
  4. Step 4: Simplify right side
    680.51x = 362,282.14
  5. Step 5: Solve for x
    x = 362,282.14/680.51
  6. Step 6: Final answer
    x = 532.37

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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.