Finding the Fourth Proportional to 1,091.98, 1,638.83 and 443.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.98 : 1,638.83 = 443.17 : x
2. Step 2: Convert to fraction form
   1,091.98/1,638.83 = 443.17/x
3. Step 3: Cross multiply
   1,091.98x = 1,638.83 × 443.17
4. Step 4: Simplify right side
   1,091.98x = 726,280.29
5. Step 5: Solve for x
   x = 726,280.29/1,091.98
6. Step 6: Final answer
   x = 665.10