Finding the Fourth Proportional to 20,629.17, 28,461.74 and 12,128.58

Step by Step Solution

1. Step 1: Write the proportion equation
   20,629.17 : 28,461.74 = 12,128.58 : x
2. Step 2: Convert to fraction form
   20,629.17/28,461.74 = 12,128.58/x
3. Step 3: Cross multiply
   20,629.17x = 28,461.74 × 12,128.58
4. Step 4: Simplify right side
   20,629.17x = 345,200,429.89
5. Step 5: Solve for x
   x = 345,200,429.89/20,629.17
6. Step 6: Final answer
   x = 16,733.61