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Finding the Fourth Proportional to 389.40, 584.16 and 129.46

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Solution

The fourth proportional to 389.40, 584.16 and 129.46 is: 194.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.40 : 584.16 = 129.46 : x
  2. Step 2: Convert to fraction form
    389.40/584.16 = 129.46/x
  3. Step 3: Cross multiply
    389.40x = 584.16 × 129.46
  4. Step 4: Simplify right side
    389.40x = 75,625.35
  5. Step 5: Solve for x
    x = 75,625.35/389.40
  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.