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Finding the Fourth Proportional to 640.42, 960.09 and 394.09

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Solution

The fourth proportional to 640.42, 960.09 and 394.09 is: 590.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.42 : 960.09 = 394.09 : x
  2. Step 2: Convert to fraction form
    640.42/960.09 = 394.09/x
  3. Step 3: Cross multiply
    640.42x = 960.09 × 394.09
  4. Step 4: Simplify right side
    640.42x = 378,361.87
  5. Step 5: Solve for x
    x = 378,361.87/640.42
  6. Step 6: Final answer
    x = 590.80

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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.