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Finding the Fourth Proportional to 644.64, 889.92 and 382.80

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Solution

The fourth proportional to 644.64, 889.92 and 382.80 is: 528.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.64 : 889.92 = 382.80 : x
  2. Step 2: Convert to fraction form
    644.64/889.92 = 382.80/x
  3. Step 3: Cross multiply
    644.64x = 889.92 × 382.80
  4. Step 4: Simplify right side
    644.64x = 340,661.38
  5. Step 5: Solve for x
    x = 340,661.38/644.64
  6. Step 6: Final answer
    x = 528.45

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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.