Finding the Fourth Proportional to 443.20, 610.72 and 326.56

Step by Step Solution

1. Step 1: Write the proportion equation
   443.20 : 610.72 = 326.56 : x
2. Step 2: Convert to fraction form
   443.20/610.72 = 326.56/x
3. Step 3: Cross multiply
   443.20x = 610.72 × 326.56
4. Step 4: Simplify right side
   443.20x = 199,436.72
5. Step 5: Solve for x
   x = 199,436.72/443.20
6. Step 6: Final answer
   x = 449.99