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Finding the Fourth Proportional to 485.31, 668.97 and 391.62

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Solution

The fourth proportional to 485.31, 668.97 and 391.62 is: 539.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.31 : 668.97 = 391.62 : x
  2. Step 2: Convert to fraction form
    485.31/668.97 = 391.62/x
  3. Step 3: Cross multiply
    485.31x = 668.97 × 391.62
  4. Step 4: Simplify right side
    485.31x = 261,982.03
  5. Step 5: Solve for x
    x = 261,982.03/485.31
  6. Step 6: Final answer
    x = 539.82

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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.