Finding the Fourth Proportional to 2,640.02, 3,960.62 and 1,406.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,640.02 : 3,960.62 = 1,406.78 : x
2. Step 2: Convert to fraction form
   2,640.02/3,960.62 = 1,406.78/x
3. Step 3: Cross multiply
   2,640.02x = 3,960.62 × 1,406.78
4. Step 4: Simplify right side
   2,640.02x = 5,571,704.72
5. Step 5: Solve for x
   x = 5,571,704.72/2,640.02
6. Step 6: Final answer
   x = 2,110.48