Finding the Fourth Proportional to 21,916.89, 30,243.79 and 12,357.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,916.89 : 30,243.79 = 12,357.12 : x
2. Step 2: Convert to fraction form
   21,916.89/30,243.79 = 12,357.12/x
3. Step 3: Cross multiply
   21,916.89x = 30,243.79 × 12,357.12
4. Step 4: Simplify right side
   21,916.89x = 373,726,142.28
5. Step 5: Solve for x
   x = 373,726,142.28/21,916.89
6. Step 6: Final answer
   x = 17,051.97