Finding the Fourth Proportional to 11,439.02, 17,136.31 and 8,431.59

Step by Step Solution

1. Step 1: Write the proportion equation
   11,439.02 : 17,136.31 = 8,431.59 : x
2. Step 2: Convert to fraction form
   11,439.02/17,136.31 = 8,431.59/x
3. Step 3: Cross multiply
   11,439.02x = 17,136.31 × 8,431.59
4. Step 4: Simplify right side
   11,439.02x = 144,486,399.02
5. Step 5: Solve for x
   x = 144,486,399.02/11,439.02
6. Step 6: Final answer
   x = 12,631.01