Finding the Fourth Proportional to 21,601.31, 32,328.78 and 13,286.60

Step by Step Solution

1. Step 1: Write the proportion equation
   21,601.31 : 32,328.78 = 13,286.60 : x
2. Step 2: Convert to fraction form
   21,601.31/32,328.78 = 13,286.60/x
3. Step 3: Cross multiply
   21,601.31x = 32,328.78 × 13,286.60
4. Step 4: Simplify right side
   21,601.31x = 429,539,568.35
5. Step 5: Solve for x
   x = 429,539,568.35/21,601.31
6. Step 6: Final answer
   x = 19,884.89