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Finding the Fourth Proportional to 408.16, 609.40 and 405.28

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Solution

The fourth proportional to 408.16, 609.40 and 405.28 is: 605.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.16 : 609.40 = 405.28 : x
  2. Step 2: Convert to fraction form
    408.16/609.40 = 405.28/x
  3. Step 3: Cross multiply
    408.16x = 609.40 × 405.28
  4. Step 4: Simplify right side
    408.16x = 246,976.05
  5. Step 5: Solve for x
    x = 246,976.05/408.16
  6. Step 6: Final answer
    x = 605.09

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.