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Finding the Fourth Proportional to 389.45, 584.18 and 129.47

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Solution

The fourth proportional to 389.45, 584.18 and 129.47 is: 194.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.45 : 584.18 = 129.47 : x
  2. Step 2: Convert to fraction form
    389.45/584.18 = 129.47/x
  3. Step 3: Cross multiply
    389.45x = 584.18 × 129.47
  4. Step 4: Simplify right side
    389.45x = 75,633.14
  5. Step 5: Solve for x
    x = 75,633.14/389.45
  6. Step 6: Final answer
    x = 194.21

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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.