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Finding the Fourth Proportional to 215.92, 323.88 and 85.92

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Solution

The fourth proportional to 215.92, 323.88 and 85.92 is: 128.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.92 : 323.88 = 85.92 : x
  2. Step 2: Convert to fraction form
    215.92/323.88 = 85.92/x
  3. Step 3: Cross multiply
    215.92x = 323.88 × 85.92
  4. Step 4: Simplify right side
    215.92x = 27,826.56
  5. Step 5: Solve for x
    x = 27,826.56/215.92
  6. Step 6: Final answer
    x = 128.87

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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.