Finding the Fourth Proportional to 2,105.09, 2,906.24 and 1,397.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.09 : 2,906.24 = 1,397.90 : x
2. Step 2: Convert to fraction form
   2,105.09/2,906.24 = 1,397.90/x
3. Step 3: Cross multiply
   2,105.09x = 2,906.24 × 1,397.90
4. Step 4: Simplify right side
   2,105.09x = 4,062,632.90
5. Step 5: Solve for x
   x = 4,062,632.90/2,105.09
6. Step 6: Final answer
   x = 1,929.91