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Finding the Fourth Proportional to 644.71, 889.79 and 408.70

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Solution

The fourth proportional to 644.71, 889.79 and 408.70 is: 564.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.71 : 889.79 = 408.70 : x
  2. Step 2: Convert to fraction form
    644.71/889.79 = 408.70/x
  3. Step 3: Cross multiply
    644.71x = 889.79 × 408.70
  4. Step 4: Simplify right side
    644.71x = 363,651.24
  5. Step 5: Solve for x
    x = 363,651.24/644.71
  6. Step 6: Final answer
    x = 564.05

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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.