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Finding the Fourth Proportional to 389.79, 584.57 and 321.15

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Solution

The fourth proportional to 389.79, 584.57 and 321.15 is: 481.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.79 : 584.57 = 321.15 : x
  2. Step 2: Convert to fraction form
    389.79/584.57 = 321.15/x
  3. Step 3: Cross multiply
    389.79x = 584.57 × 321.15
  4. Step 4: Simplify right side
    389.79x = 187,732.54
  5. Step 5: Solve for x
    x = 187,732.54/389.79
  6. Step 6: Final answer
    x = 481.62

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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.