Finding the Fourth Proportional to 10,991.67, 15,156.24 and 7,960.80

Step by Step Solution

1. Step 1: Write the proportion equation
   10,991.67 : 15,156.24 = 7,960.80 : x
2. Step 2: Convert to fraction form
   10,991.67/15,156.24 = 7,960.80/x
3. Step 3: Cross multiply
   10,991.67x = 15,156.24 × 7,960.80
4. Step 4: Simplify right side
   10,991.67x = 120,655,825.25
5. Step 5: Solve for x
   x = 120,655,825.25/10,991.67
6. Step 6: Final answer
   x = 10,977.02