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Finding the Fourth Proportional to 640.61, 961.37 and 478.41

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Solution

The fourth proportional to 640.61, 961.37 and 478.41 is: 717.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.61 : 961.37 = 478.41 : x
  2. Step 2: Convert to fraction form
    640.61/961.37 = 478.41/x
  3. Step 3: Cross multiply
    640.61x = 961.37 × 478.41
  4. Step 4: Simplify right side
    640.61x = 459,924.82
  5. Step 5: Solve for x
    x = 459,924.82/640.61
  6. Step 6: Final answer
    x = 717.95

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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.