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Finding the Fourth Proportional to 644.20, 965.97 and 211.30

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Solution

The fourth proportional to 644.20, 965.97 and 211.30 is: 316.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.20 : 965.97 = 211.30 : x
  2. Step 2: Convert to fraction form
    644.20/965.97 = 211.30/x
  3. Step 3: Cross multiply
    644.20x = 965.97 × 211.30
  4. Step 4: Simplify right side
    644.20x = 204,109.46
  5. Step 5: Solve for x
    x = 204,109.46/644.20
  6. Step 6: Final answer
    x = 316.84

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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.