Finding the Fourth Proportional to 8,131.45, 12,128.47 and 7,885.35

Step by Step Solution

1. Step 1: Write the proportion equation
   8,131.45 : 12,128.47 = 7,885.35 : x
2. Step 2: Convert to fraction form
   8,131.45/12,128.47 = 7,885.35/x
3. Step 3: Cross multiply
   8,131.45x = 12,128.47 × 7,885.35
4. Step 4: Simplify right side
   8,131.45x = 95,637,230.91
5. Step 5: Solve for x
   x = 95,637,230.91/8,131.45
6. Step 6: Final answer
   x = 11,761.40