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Finding the Fourth Proportional to 428.00, 641.39 and 211.73

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Solution

The fourth proportional to 428.00, 641.39 and 211.73 is: 317.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.00 : 641.39 = 211.73 : x
  2. Step 2: Convert to fraction form
    428.00/641.39 = 211.73/x
  3. Step 3: Cross multiply
    428.00x = 641.39 × 211.73
  4. Step 4: Simplify right side
    428.00x = 135,797.24
  5. Step 5: Solve for x
    x = 135,797.24/428.00
  6. Step 6: Final answer
    x = 317.29

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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.