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Finding the Fourth Proportional to 644.67, 889.80 and 396.15

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Solution

The fourth proportional to 644.67, 889.80 and 396.15 is: 546.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.67 : 889.80 = 396.15 : x
  2. Step 2: Convert to fraction form
    644.67/889.80 = 396.15/x
  3. Step 3: Cross multiply
    644.67x = 889.80 × 396.15
  4. Step 4: Simplify right side
    644.67x = 352,494.27
  5. Step 5: Solve for x
    x = 352,494.27/644.67
  6. Step 6: Final answer
    x = 546.78

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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.