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Finding the Fourth Proportional to 644.67, 965.21 and 427.95

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Solution

The fourth proportional to 644.67, 965.21 and 427.95 is: 640.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.67 : 965.21 = 427.95 : x
  2. Step 2: Convert to fraction form
    644.67/965.21 = 427.95/x
  3. Step 3: Cross multiply
    644.67x = 965.21 × 427.95
  4. Step 4: Simplify right side
    644.67x = 413,059.48
  5. Step 5: Solve for x
    x = 413,059.48/644.67
  6. Step 6: Final answer
    x = 640.73

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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.