Finding the Fourth Proportional to 21,233.93, 31,816.25 and 12,916.49

Step by Step Solution

1. Step 1: Write the proportion equation
   21,233.93 : 31,816.25 = 12,916.49 : x
2. Step 2: Convert to fraction form
   21,233.93/31,816.25 = 12,916.49/x
3. Step 3: Cross multiply
   21,233.93x = 31,816.25 × 12,916.49
4. Step 4: Simplify right side
   21,233.93x = 410,954,051.30
5. Step 5: Solve for x
   x = 410,954,051.30/21,233.93
6. Step 6: Final answer
   x = 19,353.65