Finding the Fourth Proportional to 2,105.81, 2,905.98 and 1,161.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.81 : 2,905.98 = 1,161.57 : x
2. Step 2: Convert to fraction form
   2,105.81/2,905.98 = 1,161.57/x
3. Step 3: Cross multiply
   2,105.81x = 2,905.98 × 1,161.57
4. Step 4: Simplify right side
   2,105.81x = 3,375,499.19
5. Step 5: Solve for x
   x = 3,375,499.19/2,105.81
6. Step 6: Final answer
   x = 1,602.95