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Finding the Fourth Proportional to 644.76, 889.96 and 408.76

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Solution

The fourth proportional to 644.76, 889.96 and 408.76 is: 564.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.76 : 889.96 = 408.76 : x
  2. Step 2: Convert to fraction form
    644.76/889.96 = 408.76/x
  3. Step 3: Cross multiply
    644.76x = 889.96 × 408.76
  4. Step 4: Simplify right side
    644.76x = 363,780.05
  5. Step 5: Solve for x
    x = 363,780.05/644.76
  6. Step 6: Final answer
    x = 564.21

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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.