Finding the Fourth Proportional to 2,640.48, 3,960.90 and 996.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,640.48 : 3,960.90 = 996.72 : x
2. Step 2: Convert to fraction form
   2,640.48/3,960.90 = 996.72/x
3. Step 3: Cross multiply
   2,640.48x = 3,960.90 × 996.72
4. Step 4: Simplify right side
   2,640.48x = 3,947,908.25
5. Step 5: Solve for x
   x = 3,947,908.25/2,640.48
6. Step 6: Final answer
   x = 1,495.15