Finding the Fourth Proportional to 10,990.43, 16,458.31 and 7,688.06

Step by Step Solution

1. Step 1: Write the proportion equation
   10,990.43 : 16,458.31 = 7,688.06 : x
2. Step 2: Convert to fraction form
   10,990.43/16,458.31 = 7,688.06/x
3. Step 3: Cross multiply
   10,990.43x = 16,458.31 × 7,688.06
4. Step 4: Simplify right side
   10,990.43x = 126,532,513.15
5. Step 5: Solve for x
   x = 126,532,513.15/10,990.43
6. Step 6: Final answer
   x = 11,512.97