Finding the Fourth Proportional to 2,803.72, 3,859.92 and 2,665.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,803.72 : 3,859.92 = 2,665.20 : x
2. Step 2: Convert to fraction form
   2,803.72/3,859.92 = 2,665.20/x
3. Step 3: Cross multiply
   2,803.72x = 3,859.92 × 2,665.20
4. Step 4: Simplify right side
   2,803.72x = 10,287,458.78
5. Step 5: Solve for x
   x = 10,287,458.78/2,803.72
6. Step 6: Final answer
   x = 3,669.22