Finding the Fourth Proportional to 2,105.58, 3,158.23 and 821.97

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.58 : 3,158.23 = 821.97 : x
2. Step 2: Convert to fraction form
   2,105.58/3,158.23 = 821.97/x
3. Step 3: Cross multiply
   2,105.58x = 3,158.23 × 821.97
4. Step 4: Simplify right side
   2,105.58x = 2,595,969.40
5. Step 5: Solve for x
   x = 2,595,969.40/2,105.58
6. Step 6: Final answer
   x = 1,232.90