Finding the Fourth Proportional to 12,072.26, 16,644.15 and 7,815.78

Step by Step Solution

1. Step 1: Write the proportion equation
   12,072.26 : 16,644.15 = 7,815.78 : x
2. Step 2: Convert to fraction form
   12,072.26/16,644.15 = 7,815.78/x
3. Step 3: Cross multiply
   12,072.26x = 16,644.15 × 7,815.78
4. Step 4: Simplify right side
   12,072.26x = 130,087,014.69
5. Step 5: Solve for x
   x = 130,087,014.69/12,072.26
6. Step 6: Final answer
   x = 10,775.70