Finding the Fourth Proportional to 2,105.76, 3,158.79 and 873.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.76 : 3,158.79 = 873.21 : x
2. Step 2: Convert to fraction form
   2,105.76/3,158.79 = 873.21/x
3. Step 3: Cross multiply
   2,105.76x = 3,158.79 × 873.21
4. Step 4: Simplify right side
   2,105.76x = 2,758,287.02
5. Step 5: Solve for x
   x = 2,758,287.02/2,105.76
6. Step 6: Final answer
   x = 1,309.88