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Finding the Fourth Proportional to 638.23, 879.39 and 490.60

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Solution

The fourth proportional to 638.23, 879.39 and 490.60 is: 675.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.23 : 879.39 = 490.60 : x
  2. Step 2: Convert to fraction form
    638.23/879.39 = 490.60/x
  3. Step 3: Cross multiply
    638.23x = 879.39 × 490.60
  4. Step 4: Simplify right side
    638.23x = 431,428.73
  5. Step 5: Solve for x
    x = 431,428.73/638.23
  6. Step 6: Final answer
    x = 675.98

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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.