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Finding the Fourth Proportional to 640.30, 959.84 and 408.54

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Solution

The fourth proportional to 640.30, 959.84 and 408.54 is: 612.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.30 : 959.84 = 408.54 : x
  2. Step 2: Convert to fraction form
    640.30/959.84 = 408.54/x
  3. Step 3: Cross multiply
    640.30x = 959.84 × 408.54
  4. Step 4: Simplify right side
    640.30x = 392,126.19
  5. Step 5: Solve for x
    x = 392,126.19/640.30
  6. Step 6: Final answer
    x = 612.41

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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.