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Finding the Fourth Proportional to 639.87, 883.20 and 378.03

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Solution

The fourth proportional to 639.87, 883.20 and 378.03 is: 521.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.87 : 883.20 = 378.03 : x
  2. Step 2: Convert to fraction form
    639.87/883.20 = 378.03/x
  3. Step 3: Cross multiply
    639.87x = 883.20 × 378.03
  4. Step 4: Simplify right side
    639.87x = 333,876.10
  5. Step 5: Solve for x
    x = 333,876.10/639.87
  6. Step 6: Final answer
    x = 521.79

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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.