Finding the Fourth Proportional to 11,661.57, 16,080.25 and 7,878.16

Step by Step Solution

1. Step 1: Write the proportion equation
   11,661.57 : 16,080.25 = 7,878.16 : x
2. Step 2: Convert to fraction form
   11,661.57/16,080.25 = 7,878.16/x
3. Step 3: Cross multiply
   11,661.57x = 16,080.25 × 7,878.16
4. Step 4: Simplify right side
   11,661.57x = 126,682,782.34
5. Step 5: Solve for x
   x = 126,682,782.34/11,661.57
6. Step 6: Final answer
   x = 10,863.27