Finding the Fourth Proportional to 2,105.89, 2,906.15 and 1,161.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.89 : 2,906.15 = 1,161.72 : x
2. Step 2: Convert to fraction form
   2,105.89/2,906.15 = 1,161.72/x
3. Step 3: Cross multiply
   2,105.89x = 2,906.15 × 1,161.72
4. Step 4: Simplify right side
   2,105.89x = 3,376,132.58
5. Step 5: Solve for x
   x = 3,376,132.58/2,105.89
6. Step 6: Final answer
   x = 1,603.19