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Finding the Fourth Proportional to 644.64, 889.20 and 408.60

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Solution

The fourth proportional to 644.64, 889.20 and 408.60 is: 563.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.64 : 889.20 = 408.60 : x
  2. Step 2: Convert to fraction form
    644.64/889.20 = 408.60/x
  3. Step 3: Cross multiply
    644.64x = 889.20 × 408.60
  4. Step 4: Simplify right side
    644.64x = 363,327.12
  5. Step 5: Solve for x
    x = 363,327.12/644.64
  6. Step 6: Final answer
    x = 563.61

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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.