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Finding the Fourth Proportional to 381.79, 572.68 and 138.22

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Solution

The fourth proportional to 381.79, 572.68 and 138.22 is: 207.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.79 : 572.68 = 138.22 : x
  2. Step 2: Convert to fraction form
    381.79/572.68 = 138.22/x
  3. Step 3: Cross multiply
    381.79x = 572.68 × 138.22
  4. Step 4: Simplify right side
    381.79x = 79,153.31
  5. Step 5: Solve for x
    x = 79,153.31/381.79
  6. Step 6: Final answer
    x = 207.32

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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.