Finding the Fourth Proportional to 9,990.83, 13,787.67 and 5,453.78

Step by Step Solution

1. Step 1: Write the proportion equation
   9,990.83 : 13,787.67 = 5,453.78 : x
2. Step 2: Convert to fraction form
   9,990.83/13,787.67 = 5,453.78/x
3. Step 3: Cross multiply
   9,990.83x = 13,787.67 × 5,453.78
4. Step 4: Simplify right side
   9,990.83x = 75,194,863.59
5. Step 5: Solve for x
   x = 75,194,863.59/9,990.83
6. Step 6: Final answer
   x = 7,526.39