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Finding the Fourth Proportional to 216.09, 323.79 and 129.21

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Solution

The fourth proportional to 216.09, 323.79 and 129.21 is: 193.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.09 : 323.79 = 129.21 : x
  2. Step 2: Convert to fraction form
    216.09/323.79 = 129.21/x
  3. Step 3: Cross multiply
    216.09x = 323.79 × 129.21
  4. Step 4: Simplify right side
    216.09x = 41,836.91
  5. Step 5: Solve for x
    x = 41,836.91/216.09
  6. Step 6: Final answer
    x = 193.61

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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.