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Finding the Fourth Proportional to 639.88, 883.05 and 378.05

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Solution

The fourth proportional to 639.88, 883.05 and 378.05 is: 521.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.88 : 883.05 = 378.05 : x
  2. Step 2: Convert to fraction form
    639.88/883.05 = 378.05/x
  3. Step 3: Cross multiply
    639.88x = 883.05 × 378.05
  4. Step 4: Simplify right side
    639.88x = 333,837.05
  5. Step 5: Solve for x
    x = 333,837.05/639.88
  6. Step 6: Final answer
    x = 521.72

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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.