Finding the Fourth Proportional to 23,139.05, 31,931.91 and 12,528.68

Step by Step Solution

1. Step 1: Write the proportion equation
   23,139.05 : 31,931.91 = 12,528.68 : x
2. Step 2: Convert to fraction form
   23,139.05/31,931.91 = 12,528.68/x
3. Step 3: Cross multiply
   23,139.05x = 31,931.91 × 12,528.68
4. Step 4: Simplify right side
   23,139.05x = 400,064,522.52
5. Step 5: Solve for x
   x = 400,064,522.52/23,139.05
6. Step 6: Final answer
   x = 17,289.59