Finding the Fourth Proportional to 8,469.59, 12,701.69 and 7,916.78

Step by Step Solution

1. Step 1: Write the proportion equation
   8,469.59 : 12,701.69 = 7,916.78 : x
2. Step 2: Convert to fraction form
   8,469.59/12,701.69 = 7,916.78/x
3. Step 3: Cross multiply
   8,469.59x = 12,701.69 × 7,916.78
4. Step 4: Simplify right side
   8,469.59x = 100,556,480.30
5. Step 5: Solve for x
   x = 100,556,480.30/8,469.59
6. Step 6: Final answer
   x = 11,872.65