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Finding the Fourth Proportional to 389.39, 584.15 and 145.85

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Solution

The fourth proportional to 389.39, 584.15 and 145.85 is: 218.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.39 : 584.15 = 145.85 : x
  2. Step 2: Convert to fraction form
    389.39/584.15 = 145.85/x
  3. Step 3: Cross multiply
    389.39x = 584.15 × 145.85
  4. Step 4: Simplify right side
    389.39x = 85,194.63
  5. Step 5: Solve for x
    x = 85,194.63/389.39
  6. Step 6: Final answer
    x = 218.79

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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.