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Finding the Fourth Proportional to 490.39, 738.91 and 405.61

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Solution

The fourth proportional to 490.39, 738.91 and 405.61 is: 611.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    490.39 : 738.91 = 405.61 : x
  2. Step 2: Convert to fraction form
    490.39/738.91 = 405.61/x
  3. Step 3: Cross multiply
    490.39x = 738.91 × 405.61
  4. Step 4: Simplify right side
    490.39x = 299,709.29
  5. Step 5: Solve for x
    x = 299,709.29/490.39
  6. Step 6: Final answer
    x = 611.17

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.