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Finding the Fourth Proportional to 639.28, 882.16 and 355.72

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Solution

The fourth proportional to 639.28, 882.16 and 355.72 is: 490.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.28 : 882.16 = 355.72 : x
  2. Step 2: Convert to fraction form
    639.28/882.16 = 355.72/x
  3. Step 3: Cross multiply
    639.28x = 882.16 × 355.72
  4. Step 4: Simplify right side
    639.28x = 313,797.54
  5. Step 5: Solve for x
    x = 313,797.54/639.28
  6. Step 6: Final answer
    x = 490.86

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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.