Finding the Fourth Proportional to 21,656.30, 32,478.71 and 8,508.78

Step by Step Solution

1. Step 1: Write the proportion equation
   21,656.30 : 32,478.71 = 8,508.78 : x
2. Step 2: Convert to fraction form
   21,656.30/32,478.71 = 8,508.78/x
3. Step 3: Cross multiply
   21,656.30x = 32,478.71 × 8,508.78
4. Step 4: Simplify right side
   21,656.30x = 276,354,325.19
5. Step 5: Solve for x
   x = 276,354,325.19/21,656.30
6. Step 6: Final answer
   x = 12,760.92