Finding the Fourth Proportional to 20,508.12, 28,300.86 and 12,123

Step by Step Solution

1. Step 1: Write the proportion equation
   20,508.12 : 28,300.86 = 12,123 : x
2. Step 2: Convert to fraction form
   20,508.12/28,300.86 = 12,123/x
3. Step 3: Cross multiply
   20,508.12x = 28,300.86 × 12,123
4. Step 4: Simplify right side
   20,508.12x = 343,091,325.78
5. Step 5: Solve for x
   x = 343,091,325.78/20,508.12
6. Step 6: Final answer
   x = 16,729.54