Finding the Fourth Proportional to 321.30, 443.31 and 196.91

Step by Step Solution

1. Step 1: Write the proportion equation
   321.30 : 443.31 = 196.91 : x
2. Step 2: Convert to fraction form
   321.30/443.31 = 196.91/x
3. Step 3: Cross multiply
   321.30x = 443.31 × 196.91
4. Step 4: Simplify right side
   321.30x = 87,292.17
5. Step 5: Solve for x
   x = 87,292.17/321.30
6. Step 6: Final answer
   x = 271.69