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Finding the Fourth Proportional to 389.64, 584.56 and 129.68

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Solution

The fourth proportional to 389.64, 584.56 and 129.68 is: 194.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.64 : 584.56 = 129.68 : x
  2. Step 2: Convert to fraction form
    389.64/584.56 = 129.68/x
  3. Step 3: Cross multiply
    389.64x = 584.56 × 129.68
  4. Step 4: Simplify right side
    389.64x = 75,805.74
  5. Step 5: Solve for x
    x = 75,805.74/389.64
  6. Step 6: Final answer
    x = 194.55

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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.