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Finding the Fourth Proportional to 644.90, 889.67 and 409.15

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Solution

The fourth proportional to 644.90, 889.67 and 409.15 is: 564.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.90 : 889.67 = 409.15 : x
  2. Step 2: Convert to fraction form
    644.90/889.67 = 409.15/x
  3. Step 3: Cross multiply
    644.90x = 889.67 × 409.15
  4. Step 4: Simplify right side
    644.90x = 364,001.99
  5. Step 5: Solve for x
    x = 364,001.99/644.90
  6. Step 6: Final answer
    x = 564.43

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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.