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Finding the Fourth Proportional to 644.18, 889.17 and 408.20

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Solution

The fourth proportional to 644.18, 889.17 and 408.20 is: 563.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.18 : 889.17 = 408.20 : x
  2. Step 2: Convert to fraction form
    644.18/889.17 = 408.20/x
  3. Step 3: Cross multiply
    644.18x = 889.17 × 408.20
  4. Step 4: Simplify right side
    644.18x = 362,959.19
  5. Step 5: Solve for x
    x = 362,959.19/644.18
  6. Step 6: Final answer
    x = 563.44

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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.