Finding the Fourth Proportional to 16,861.41, 25,272.41 and 12,688

Step by Step Solution

1. Step 1: Write the proportion equation
   16,861.41 : 25,272.41 = 12,688 : x
2. Step 2: Convert to fraction form
   16,861.41/25,272.41 = 12,688/x
3. Step 3: Cross multiply
   16,861.41x = 25,272.41 × 12,688
4. Step 4: Simplify right side
   16,861.41x = 320,656,369.80
5. Step 5: Solve for x
   x = 320,656,369.80/16,861.41
6. Step 6: Final answer
   x = 19,017.18