Finding the Fourth Proportional to 23,130.72, 31,918.86 and 12,921.62

Step by Step Solution

1. Step 1: Write the proportion equation
   23,130.72 : 31,918.86 = 12,921.62 : x
2. Step 2: Convert to fraction form
   23,130.72/31,918.86 = 12,921.62/x
3. Step 3: Cross multiply
   23,130.72x = 31,918.86 × 12,921.62
4. Step 4: Simplify right side
   23,130.72x = 412,443,220.16
5. Step 5: Solve for x
   x = 412,443,220.16/23,130.72
6. Step 6: Final answer
   x = 17,830.97