Finding the Fourth Proportional to 11,379.48, 17,129.61 and 8,115.16

Step by Step Solution

1. Step 1: Write the proportion equation
   11,379.48 : 17,129.61 = 8,115.16 : x
2. Step 2: Convert to fraction form
   11,379.48/17,129.61 = 8,115.16/x
3. Step 3: Cross multiply
   11,379.48x = 17,129.61 × 8,115.16
4. Step 4: Simplify right side
   11,379.48x = 139,009,525.89
5. Step 5: Solve for x
   x = 139,009,525.89/11,379.48
6. Step 6: Final answer
   x = 12,215.81