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Finding the Fourth Proportional to 644.68, 890.09 and 382.78

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Solution

The fourth proportional to 644.68, 890.09 and 382.78 is: 528.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.68 : 890.09 = 382.78 : x
  2. Step 2: Convert to fraction form
    644.68/890.09 = 382.78/x
  3. Step 3: Cross multiply
    644.68x = 890.09 × 382.78
  4. Step 4: Simplify right side
    644.68x = 340,708.65
  5. Step 5: Solve for x
    x = 340,708.65/644.68
  6. Step 6: Final answer
    x = 528.49

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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.