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Finding the Fourth Proportional to 636.78, 879.86 and 490.67

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Solution

The fourth proportional to 636.78, 879.86 and 490.67 is: 677.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.78 : 879.86 = 490.67 : x
  2. Step 2: Convert to fraction form
    636.78/879.86 = 490.67/x
  3. Step 3: Cross multiply
    636.78x = 879.86 × 490.67
  4. Step 4: Simplify right side
    636.78x = 431,718.45
  5. Step 5: Solve for x
    x = 431,718.45/636.78
  6. Step 6: Final answer
    x = 677.97

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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.