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Finding the Fourth Proportional to 490.72, 677.20 and 280.90

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Solution

The fourth proportional to 490.72, 677.20 and 280.90 is: 387.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    490.72 : 677.20 = 280.90 : x
  2. Step 2: Convert to fraction form
    490.72/677.20 = 280.90/x
  3. Step 3: Cross multiply
    490.72x = 677.20 × 280.90
  4. Step 4: Simplify right side
    490.72x = 190,223.46
  5. Step 5: Solve for x
    x = 190,223.46/490.72
  6. Step 6: Final answer
    x = 387.64

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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.