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Finding the Fourth Proportional to 644.61, 889.75 and 382.78

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Solution

The fourth proportional to 644.61, 889.75 and 382.78 is: 528.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.61 : 889.75 = 382.78 : x
  2. Step 2: Convert to fraction form
    644.61/889.75 = 382.78/x
  3. Step 3: Cross multiply
    644.61x = 889.75 × 382.78
  4. Step 4: Simplify right side
    644.61x = 340,578.51
  5. Step 5: Solve for x
    x = 340,578.51/644.61
  6. Step 6: Final answer
    x = 528.35

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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.