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Finding the Fourth Proportional to 399.91, 551.28 and 321.19

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Solution

The fourth proportional to 399.91, 551.28 and 321.19 is: 442.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.91 : 551.28 = 321.19 : x
  2. Step 2: Convert to fraction form
    399.91/551.28 = 321.19/x
  3. Step 3: Cross multiply
    399.91x = 551.28 × 321.19
  4. Step 4: Simplify right side
    399.91x = 177,067.26
  5. Step 5: Solve for x
    x = 177,067.26/399.91
  6. Step 6: Final answer
    x = 442.77

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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.