Finding the Fourth Proportional to 2,105.88, 3,158.60 and 646.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.88 : 3,158.60 = 646.05 : x
2. Step 2: Convert to fraction form
   2,105.88/3,158.60 = 646.05/x
3. Step 3: Cross multiply
   2,105.88x = 3,158.60 × 646.05
4. Step 4: Simplify right side
   2,105.88x = 2,040,610.30
5. Step 5: Solve for x
   x = 2,040,610.30/2,105.88
6. Step 6: Final answer
   x = 969.01