Finding the Fourth Proportional to 11,039.88, 15,219.42 and 7,890.60

Step by Step Solution

1. Step 1: Write the proportion equation
   11,039.88 : 15,219.42 = 7,890.60 : x
2. Step 2: Convert to fraction form
   11,039.88/15,219.42 = 7,890.60/x
3. Step 3: Cross multiply
   11,039.88x = 15,219.42 × 7,890.60
4. Step 4: Simplify right side
   11,039.88x = 120,090,355.45
5. Step 5: Solve for x
   x = 120,090,355.45/11,039.88
6. Step 6: Final answer
   x = 10,877.87