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Finding the Fourth Proportional to 381.86, 572.65 and 138.59

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Solution

The fourth proportional to 381.86, 572.65 and 138.59 is: 207.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.86 : 572.65 = 138.59 : x
  2. Step 2: Convert to fraction form
    381.86/572.65 = 138.59/x
  3. Step 3: Cross multiply
    381.86x = 572.65 × 138.59
  4. Step 4: Simplify right side
    381.86x = 79,360.35
  5. Step 5: Solve for x
    x = 79,360.35/381.86
  6. Step 6: Final answer
    x = 207.83

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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.