Finding the Fourth Proportional to 21,788.68, 32,693.82 and 8,640.76

Step by Step Solution

1. Step 1: Write the proportion equation
   21,788.68 : 32,693.82 = 8,640.76 : x
2. Step 2: Convert to fraction form
   21,788.68/32,693.82 = 8,640.76/x
3. Step 3: Cross multiply
   21,788.68x = 32,693.82 × 8,640.76
4. Step 4: Simplify right side
   21,788.68x = 282,499,245.43
5. Step 5: Solve for x
   x = 282,499,245.43/21,788.68
6. Step 6: Final answer
   x = 12,965.42