Finding the Fourth Proportional to 21,093.56, 31,640.41 and 7,942.40

Step by Step Solution

1. Step 1: Write the proportion equation
   21,093.56 : 31,640.41 = 7,942.40 : x
2. Step 2: Convert to fraction form
   21,093.56/31,640.41 = 7,942.40/x
3. Step 3: Cross multiply
   21,093.56x = 31,640.41 × 7,942.40
4. Step 4: Simplify right side
   21,093.56x = 251,300,792.38
5. Step 5: Solve for x
   x = 251,300,792.38/21,093.56
6. Step 6: Final answer
   x = 11,913.63