Finding the Fourth Proportional to 2,661.30, 3,992.70 and 1,200.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.30 : 3,992.70 = 1,200.42 : x
2. Step 2: Convert to fraction form
   2,661.30/3,992.70 = 1,200.42/x
3. Step 3: Cross multiply
   2,661.30x = 3,992.70 × 1,200.42
4. Step 4: Simplify right side
   2,661.30x = 4,792,916.93
5. Step 5: Solve for x
   x = 4,792,916.93/2,661.30
6. Step 6: Final answer
   x = 1,800.97