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Finding the Fourth Proportional to 644.57, 889.49 and 395.80

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Solution

The fourth proportional to 644.57, 889.49 and 395.80 is: 546.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.57 : 889.49 = 395.80 : x
  2. Step 2: Convert to fraction form
    644.57/889.49 = 395.80/x
  3. Step 3: Cross multiply
    644.57x = 889.49 × 395.80
  4. Step 4: Simplify right side
    644.57x = 352,058.91
  5. Step 5: Solve for x
    x = 352,058.91/644.57
  6. Step 6: Final answer
    x = 546.19

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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.