Finding the Fourth Proportional to 2,168.12, 2,991.77 and 1,223.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,168.12 : 2,991.77 = 1,223.96 : x
2. Step 2: Convert to fraction form
   2,168.12/2,991.77 = 1,223.96/x
3. Step 3: Cross multiply
   2,168.12x = 2,991.77 × 1,223.96
4. Step 4: Simplify right side
   2,168.12x = 3,661,785.73
5. Step 5: Solve for x
   x = 3,661,785.73/2,168.12
6. Step 6: Final answer
   x = 1,688.93