Finding the Fourth Proportional to 16,856.78, 23,256.80 and 10,891.96

Step by Step Solution

1. Step 1: Write the proportion equation
   16,856.78 : 23,256.80 = 10,891.96 : x
2. Step 2: Convert to fraction form
   16,856.78/23,256.80 = 10,891.96/x
3. Step 3: Cross multiply
   16,856.78x = 23,256.80 × 10,891.96
4. Step 4: Simplify right side
   16,856.78x = 253,312,104.42
5. Step 5: Solve for x
   x = 253,312,104.42/16,856.78
6. Step 6: Final answer
   x = 15,027.32