Finding the Fourth Proportional to 12,308.64, 16,995.60 and 9,911

Step by Step Solution

1. Step 1: Write the proportion equation
   12,308.64 : 16,995.60 = 9,911 : x
2. Step 2: Convert to fraction form
   12,308.64/16,995.60 = 9,911/x
3. Step 3: Cross multiply
   12,308.64x = 16,995.60 × 9,911
4. Step 4: Simplify right side
   12,308.64x = 168,443,391.60
5. Step 5: Solve for x
   x = 168,443,391.60/12,308.64
6. Step 6: Final answer
   x = 13,684.97