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Finding the Fourth Proportional to 644.62, 889.50 and 378.86

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Solution

The fourth proportional to 644.62, 889.50 and 378.86 is: 522.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.62 : 889.50 = 378.86 : x
  2. Step 2: Convert to fraction form
    644.62/889.50 = 378.86/x
  3. Step 3: Cross multiply
    644.62x = 889.50 × 378.86
  4. Step 4: Simplify right side
    644.62x = 336,995.97
  5. Step 5: Solve for x
    x = 336,995.97/644.62
  6. Step 6: Final answer
    x = 522.79

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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.