Finding the Fourth Proportional to 12,761.88, 17,615.78 and 7,920.37

Step by Step Solution

1. Step 1: Write the proportion equation
   12,761.88 : 17,615.78 = 7,920.37 : x
2. Step 2: Convert to fraction form
   12,761.88/17,615.78 = 7,920.37/x
3. Step 3: Cross multiply
   12,761.88x = 17,615.78 × 7,920.37
4. Step 4: Simplify right side
   12,761.88x = 139,523,495.44
5. Step 5: Solve for x
   x = 139,523,495.44/12,761.88
6. Step 6: Final answer
   x = 10,932.83