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Finding the Fourth Proportional to 399.87, 551.45 and 321.03

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Solution

The fourth proportional to 399.87, 551.45 and 321.03 is: 442.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.87 : 551.45 = 321.03 : x
  2. Step 2: Convert to fraction form
    399.87/551.45 = 321.03/x
  3. Step 3: Cross multiply
    399.87x = 551.45 × 321.03
  4. Step 4: Simplify right side
    399.87x = 177,032.80
  5. Step 5: Solve for x
    x = 177,032.80/399.87
  6. Step 6: Final answer
    x = 442.73

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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.