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Finding the Fourth Proportional to 640.31, 958.23 and 393.40

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Solution

The fourth proportional to 640.31, 958.23 and 393.40 is: 588.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.31 : 958.23 = 393.40 : x
  2. Step 2: Convert to fraction form
    640.31/958.23 = 393.40/x
  3. Step 3: Cross multiply
    640.31x = 958.23 × 393.40
  4. Step 4: Simplify right side
    640.31x = 376,966.18
  5. Step 5: Solve for x
    x = 376,966.18/640.31
  6. Step 6: Final answer
    x = 588.73

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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.