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Finding the Fourth Proportional to 644.98, 889.77 and 396.21

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Solution

The fourth proportional to 644.98, 889.77 and 396.21 is: 546.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.98 : 889.77 = 396.21 : x
  2. Step 2: Convert to fraction form
    644.98/889.77 = 396.21/x
  3. Step 3: Cross multiply
    644.98x = 889.77 × 396.21
  4. Step 4: Simplify right side
    644.98x = 352,533.36
  5. Step 5: Solve for x
    x = 352,533.36/644.98
  6. Step 6: Final answer
    x = 546.58

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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.