Finding the Fourth Proportional to 21,196.64, 31,772.16 and 13,806.56

Step by Step Solution

1. Step 1: Write the proportion equation
   21,196.64 : 31,772.16 = 13,806.56 : x
2. Step 2: Convert to fraction form
   21,196.64/31,772.16 = 13,806.56/x
3. Step 3: Cross multiply
   21,196.64x = 31,772.16 × 13,806.56
4. Step 4: Simplify right side
   21,196.64x = 438,664,233.37
5. Step 5: Solve for x
   x = 438,664,233.37/21,196.64
6. Step 6: Final answer
   x = 20,694.99