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Finding the Fourth Proportional to 490.30, 676.63 and 280.40

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Solution

The fourth proportional to 490.30, 676.63 and 280.40 is: 386.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    490.30 : 676.63 = 280.40 : x
  2. Step 2: Convert to fraction form
    490.30/676.63 = 280.40/x
  3. Step 3: Cross multiply
    490.30x = 676.63 × 280.40
  4. Step 4: Simplify right side
    490.30x = 189,727.05
  5. Step 5: Solve for x
    x = 189,727.05/490.30
  6. Step 6: Final answer
    x = 386.96

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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.