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Finding the Fourth Proportional to 427.57, 641.40 and 211.09

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Solution

The fourth proportional to 427.57, 641.40 and 211.09 is: 316.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.57 : 641.40 = 211.09 : x
  2. Step 2: Convert to fraction form
    427.57/641.40 = 211.09/x
  3. Step 3: Cross multiply
    427.57x = 641.40 × 211.09
  4. Step 4: Simplify right side
    427.57x = 135,393.13
  5. Step 5: Solve for x
    x = 135,393.13/427.57
  6. Step 6: Final answer
    x = 316.66

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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.