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Finding the Fourth Proportional to 636.21, 879.09 and 490.11

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Solution

The fourth proportional to 636.21, 879.09 and 490.11 is: 677.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.21 : 879.09 = 490.11 : x
  2. Step 2: Convert to fraction form
    636.21/879.09 = 490.11/x
  3. Step 3: Cross multiply
    636.21x = 879.09 × 490.11
  4. Step 4: Simplify right side
    636.21x = 430,846.40
  5. Step 5: Solve for x
    x = 430,846.40/636.21
  6. Step 6: Final answer
    x = 677.21

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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.