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Finding the Fourth Proportional to 644.78, 889.53 and 382.79

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Solution

The fourth proportional to 644.78, 889.53 and 382.79 is: 528.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.78 : 889.53 = 382.79 : x
  2. Step 2: Convert to fraction form
    644.78/889.53 = 382.79/x
  3. Step 3: Cross multiply
    644.78x = 889.53 × 382.79
  4. Step 4: Simplify right side
    644.78x = 340,503.19
  5. Step 5: Solve for x
    x = 340,503.19/644.78
  6. Step 6: Final answer
    x = 528.09

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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.