Finding the Fourth Proportional to 9,991.06, 13,787.81 and 5,515

Step by Step Solution

1. Step 1: Write the proportion equation
   9,991.06 : 13,787.81 = 5,515 : x
2. Step 2: Convert to fraction form
   9,991.06/13,787.81 = 5,515/x
3. Step 3: Cross multiply
   9,991.06x = 13,787.81 × 5,515
4. Step 4: Simplify right side
   9,991.06x = 76,039,772.15
5. Step 5: Solve for x
   x = 76,039,772.15/9,991.06
6. Step 6: Final answer
   x = 7,610.78