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Finding the Fourth Proportional to 490.12, 676.28 and 280.20

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Solution

The fourth proportional to 490.12, 676.28 and 280.20 is: 386.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    490.12 : 676.28 = 280.20 : x
  2. Step 2: Convert to fraction form
    490.12/676.28 = 280.20/x
  3. Step 3: Cross multiply
    490.12x = 676.28 × 280.20
  4. Step 4: Simplify right side
    490.12x = 189,493.66
  5. Step 5: Solve for x
    x = 189,493.66/490.12
  6. Step 6: Final answer
    x = 386.63

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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.