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Finding the Fourth Proportional to 721.91, 996.23 and 390.33

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Solution

The fourth proportional to 721.91, 996.23 and 390.33 is: 538.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.91 : 996.23 = 390.33 : x
  2. Step 2: Convert to fraction form
    721.91/996.23 = 390.33/x
  3. Step 3: Cross multiply
    721.91x = 996.23 × 390.33
  4. Step 4: Simplify right side
    721.91x = 388,861.92
  5. Step 5: Solve for x
    x = 388,861.92/721.91
  6. Step 6: Final answer
    x = 538.66

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.