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Finding the Fourth Proportional to 639.34, 960.61 and 408.34

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Solution

The fourth proportional to 639.34, 960.61 and 408.34 is: 613.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.34 : 960.61 = 408.34 : x
  2. Step 2: Convert to fraction form
    639.34/960.61 = 408.34/x
  3. Step 3: Cross multiply
    639.34x = 960.61 × 408.34
  4. Step 4: Simplify right side
    639.34x = 392,256.43
  5. Step 5: Solve for x
    x = 392,256.43/639.34
  6. Step 6: Final answer
    x = 613.53

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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.