Finding the Fourth Proportional to 23,128.54, 31,916.75 and 12,919.30

Step by Step Solution

1. Step 1: Write the proportion equation
   23,128.54 : 31,916.75 = 12,919.30 : x
2. Step 2: Convert to fraction form
   23,128.54/31,916.75 = 12,919.30/x
3. Step 3: Cross multiply
   23,128.54x = 31,916.75 × 12,919.30
4. Step 4: Simplify right side
   23,128.54x = 412,342,115.77
5. Step 5: Solve for x
   x = 412,342,115.77/23,128.54
6. Step 6: Final answer
   x = 17,828.28