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Finding the Fourth Proportional to 644.86, 889.90 and 379.31

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Solution

The fourth proportional to 644.86, 889.90 and 379.31 is: 523.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.86 : 889.90 = 379.31 : x
  2. Step 2: Convert to fraction form
    644.86/889.90 = 379.31/x
  3. Step 3: Cross multiply
    644.86x = 889.90 × 379.31
  4. Step 4: Simplify right side
    644.86x = 337,542.57
  5. Step 5: Solve for x
    x = 337,542.57/644.86
  6. Step 6: Final answer
    x = 523.43

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.