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Finding the Fourth Proportional to 215.43, 321.39 and 205.65

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Solution

The fourth proportional to 215.43, 321.39 and 205.65 is: 306.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.43 : 321.39 = 205.65 : x
  2. Step 2: Convert to fraction form
    215.43/321.39 = 205.65/x
  3. Step 3: Cross multiply
    215.43x = 321.39 × 205.65
  4. Step 4: Simplify right side
    215.43x = 66,093.85
  5. Step 5: Solve for x
    x = 66,093.85/215.43
  6. Step 6: Final answer
    x = 306.80

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.