Finding the Fourth Proportional to 2,106.20, 3,158.12 and 872.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.20 : 3,158.12 = 872.96 : x
2. Step 2: Convert to fraction form
   2,106.20/3,158.12 = 872.96/x
3. Step 3: Cross multiply
   2,106.20x = 3,158.12 × 872.96
4. Step 4: Simplify right side
   2,106.20x = 2,756,898.83
5. Step 5: Solve for x
   x = 2,756,898.83/2,106.20
6. Step 6: Final answer
   x = 1,308.94