Finding the Fourth Proportional to 20,608.79, 28,440.33 and 12,111.10

Step by Step Solution

1. Step 1: Write the proportion equation
   20,608.79 : 28,440.33 = 12,111.10 : x
2. Step 2: Convert to fraction form
   20,608.79/28,440.33 = 12,111.10/x
3. Step 3: Cross multiply
   20,608.79x = 28,440.33 × 12,111.10
4. Step 4: Simplify right side
   20,608.79x = 344,443,680.66
5. Step 5: Solve for x
   x = 344,443,680.66/20,608.79
6. Step 6: Final answer
   x = 16,713.44