Finding the Fourth Proportional to 1,321.22, 1,981.17 and 443.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,321.22 : 1,981.17 = 443.42 : x
2. Step 2: Convert to fraction form
   1,321.22/1,981.17 = 443.42/x
3. Step 3: Cross multiply
   1,321.22x = 1,981.17 × 443.42
4. Step 4: Simplify right side
   1,321.22x = 878,490.40
5. Step 5: Solve for x
   x = 878,490.40/1,321.22
6. Step 6: Final answer
   x = 664.91