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Finding the Fourth Proportional to 485.20, 726.84 and 408.64

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Solution

The fourth proportional to 485.20, 726.84 and 408.64 is: 612.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.20 : 726.84 = 408.64 : x
  2. Step 2: Convert to fraction form
    485.20/726.84 = 408.64/x
  3. Step 3: Cross multiply
    485.20x = 726.84 × 408.64
  4. Step 4: Simplify right side
    485.20x = 297,015.90
  5. Step 5: Solve for x
    x = 297,015.90/485.20
  6. Step 6: Final answer
    x = 612.15

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.