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Finding the Fourth Proportional to 427.91, 641.84 and 119.78

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Solution

The fourth proportional to 427.91, 641.84 and 119.78 is: 179.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.91 : 641.84 = 119.78 : x
  2. Step 2: Convert to fraction form
    427.91/641.84 = 119.78/x
  3. Step 3: Cross multiply
    427.91x = 641.84 × 119.78
  4. Step 4: Simplify right side
    427.91x = 76,879.60
  5. Step 5: Solve for x
    x = 76,879.60/427.91
  6. Step 6: Final answer
    x = 179.66

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.