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Finding the Fourth Proportional to 639.90, 882.63 and 403.79

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Solution

The fourth proportional to 639.90, 882.63 and 403.79 is: 556.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.90 : 882.63 = 403.79 : x
  2. Step 2: Convert to fraction form
    639.90/882.63 = 403.79/x
  3. Step 3: Cross multiply
    639.90x = 882.63 × 403.79
  4. Step 4: Simplify right side
    639.90x = 356,392.75
  5. Step 5: Solve for x
    x = 356,392.75/639.90
  6. Step 6: Final answer
    x = 556.95

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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.