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Finding the Fourth Proportional to 389.78, 584.75 and 115.86

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Solution

The fourth proportional to 389.78, 584.75 and 115.86 is: 173.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.78 : 584.75 = 115.86 : x
  2. Step 2: Convert to fraction form
    389.78/584.75 = 115.86/x
  3. Step 3: Cross multiply
    389.78x = 584.75 × 115.86
  4. Step 4: Simplify right side
    389.78x = 67,748.56
  5. Step 5: Solve for x
    x = 67,748.56/389.78
  6. Step 6: Final answer
    x = 173.81

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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.