Finding the Fourth Proportional to 11,158.04, 15,399.31 and 7,128.58

Step by Step Solution

1. Step 1: Write the proportion equation
   11,158.04 : 15,399.31 = 7,128.58 : x
2. Step 2: Convert to fraction form
   11,158.04/15,399.31 = 7,128.58/x
3. Step 3: Cross multiply
   11,158.04x = 15,399.31 × 7,128.58
4. Step 4: Simplify right side
   11,158.04x = 109,775,136.28
5. Step 5: Solve for x
   x = 109,775,136.28/11,158.04
6. Step 6: Final answer
   x = 9,838.21