Finding the Fourth Proportional to 5,399.19, 8,100.90 and 2,111.72

Step by Step Solution

1. Step 1: Write the proportion equation
   5,399.19 : 8,100.90 = 2,111.72 : x
2. Step 2: Convert to fraction form
   5,399.19/8,100.90 = 2,111.72/x
3. Step 3: Cross multiply
   5,399.19x = 8,100.90 × 2,111.72
4. Step 4: Simplify right side
   5,399.19x = 17,106,792.04
5. Step 5: Solve for x
   x = 17,106,792.04/5,399.19
6. Step 6: Final answer
   x = 3,168.40