Finding the Fourth Proportional to 11,391.96, 17,087.76 and 5,147.60

Step by Step Solution

1. Step 1: Write the proportion equation
   11,391.96 : 17,087.76 = 5,147.60 : x
2. Step 2: Convert to fraction form
   11,391.96/17,087.76 = 5,147.60/x
3. Step 3: Cross multiply
   11,391.96x = 17,087.76 × 5,147.60
4. Step 4: Simplify right side
   11,391.96x = 87,960,996.10
5. Step 5: Solve for x
   x = 87,960,996.10/11,391.96
6. Step 6: Final answer
   x = 7,721.32