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Finding the Fourth Proportional to 680.60, 939.28 and 385.90

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Solution

The fourth proportional to 680.60, 939.28 and 385.90 is: 532.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.60 : 939.28 = 385.90 : x
  2. Step 2: Convert to fraction form
    680.60/939.28 = 385.90/x
  3. Step 3: Cross multiply
    680.60x = 939.28 × 385.90
  4. Step 4: Simplify right side
    680.60x = 362,464.84
  5. Step 5: Solve for x
    x = 362,464.84/680.60
  6. Step 6: Final answer
    x = 532.56

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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.