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Finding the Fourth Proportional to 389.87, 584.45 and 129.71

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Solution

The fourth proportional to 389.87, 584.45 and 129.71 is: 194.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.87 : 584.45 = 129.71 : x
  2. Step 2: Convert to fraction form
    389.87/584.45 = 129.71/x
  3. Step 3: Cross multiply
    389.87x = 584.45 × 129.71
  4. Step 4: Simplify right side
    389.87x = 75,805.44
  5. Step 5: Solve for x
    x = 75,805.44/389.87
  6. Step 6: Final answer
    x = 194.44

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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.