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Finding the Fourth Proportional to 640.89, 959.90 and 396.90

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Solution

The fourth proportional to 640.89, 959.90 and 396.90 is: 594.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.89 : 959.90 = 396.90 : x
  2. Step 2: Convert to fraction form
    640.89/959.90 = 396.90/x
  3. Step 3: Cross multiply
    640.89x = 959.90 × 396.90
  4. Step 4: Simplify right side
    640.89x = 380,982.33
  5. Step 5: Solve for x
    x = 380,982.33/640.89
  6. Step 6: Final answer
    x = 594.46

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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.