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Finding the Fourth Proportional to 640.92, 961.56 and 409.80

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Solution

The fourth proportional to 640.92, 961.56 and 409.80 is: 614.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.92 : 961.56 = 409.80 : x
  2. Step 2: Convert to fraction form
    640.92/961.56 = 409.80/x
  3. Step 3: Cross multiply
    640.92x = 961.56 × 409.80
  4. Step 4: Simplify right side
    640.92x = 394,047.29
  5. Step 5: Solve for x
    x = 394,047.29/640.92
  6. Step 6: Final answer
    x = 614.82

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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.