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Finding the Fourth Proportional to 381.28, 571.20 and 218.47

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Solution

The fourth proportional to 381.28, 571.20 and 218.47 is: 327.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.28 : 571.20 = 218.47 : x
  2. Step 2: Convert to fraction form
    381.28/571.20 = 218.47/x
  3. Step 3: Cross multiply
    381.28x = 571.20 × 218.47
  4. Step 4: Simplify right side
    381.28x = 124,787.21
  5. Step 5: Solve for x
    x = 124,787.21/381.28
  6. Step 6: Final answer
    x = 327.29

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.