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Finding the Fourth Proportional to 579.12, 868.72 and 213.90

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Solution

The fourth proportional to 579.12, 868.72 and 213.90 is: 320.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    579.12 : 868.72 = 213.90 : x
  2. Step 2: Convert to fraction form
    579.12/868.72 = 213.90/x
  3. Step 3: Cross multiply
    579.12x = 868.72 × 213.90
  4. Step 4: Simplify right side
    579.12x = 185,819.21
  5. Step 5: Solve for x
    x = 185,819.21/579.12
  6. Step 6: Final answer
    x = 320.86

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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.