Finding the Fourth Proportional to 9,990, 13,784.78 and 5,513.54

Step by Step Solution

1. Step 1: Write the proportion equation
   9,990 : 13,784.78 = 5,513.54 : x
2. Step 2: Convert to fraction form
   9,990/13,784.78 = 5,513.54/x
3. Step 3: Cross multiply
   9,990x = 13,784.78 × 5,513.54
4. Step 4: Simplify right side
   9,990x = 76,002,880.78
5. Step 5: Solve for x
   x = 76,002,880.78/9,990
6. Step 6: Final answer
   x = 7,607.90