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Finding the Fourth Proportional to 381.71, 572.87 and 138.31

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Solution

The fourth proportional to 381.71, 572.87 and 138.31 is: 207.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.71 : 572.87 = 138.31 : x
  2. Step 2: Convert to fraction form
    381.71/572.87 = 138.31/x
  3. Step 3: Cross multiply
    381.71x = 572.87 × 138.31
  4. Step 4: Simplify right side
    381.71x = 79,232.56
  5. Step 5: Solve for x
    x = 79,232.56/381.71
  6. Step 6: Final answer
    x = 207.57

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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.