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Finding the Fourth Proportional to 399.36, 551.31 and 281.58

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Solution

The fourth proportional to 399.36, 551.31 and 281.58 is: 388.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.36 : 551.31 = 281.58 : x
  2. Step 2: Convert to fraction form
    399.36/551.31 = 281.58/x
  3. Step 3: Cross multiply
    399.36x = 551.31 × 281.58
  4. Step 4: Simplify right side
    399.36x = 155,234.75
  5. Step 5: Solve for x
    x = 155,234.75/399.36
  6. Step 6: Final answer
    x = 388.71

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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.