Finding the Fourth Proportional to 2,111.04, 3,168.72 and 1,278.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.04 : 3,168.72 = 1,278.90 : x
2. Step 2: Convert to fraction form
   2,111.04/3,168.72 = 1,278.90/x
3. Step 3: Cross multiply
   2,111.04x = 3,168.72 × 1,278.90
4. Step 4: Simplify right side
   2,111.04x = 4,052,476.01
5. Step 5: Solve for x
   x = 4,052,476.01/2,111.04
6. Step 6: Final answer
   x = 1,919.66