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Finding the Fourth Proportional to 644.39, 889.41 and 378.89

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Solution

The fourth proportional to 644.39, 889.41 and 378.89 is: 522.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.39 : 889.41 = 378.89 : x
  2. Step 2: Convert to fraction form
    644.39/889.41 = 378.89/x
  3. Step 3: Cross multiply
    644.39x = 889.41 × 378.89
  4. Step 4: Simplify right side
    644.39x = 336,988.55
  5. Step 5: Solve for x
    x = 336,988.55/644.39
  6. Step 6: Final answer
    x = 522.96

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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.