Finding the Fourth Proportional to 21,203.28, 31,806.72 and 5,620.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,203.28 : 31,806.72 = 5,620.72 : x
2. Step 2: Convert to fraction form
   21,203.28/31,806.72 = 5,620.72/x
3. Step 3: Cross multiply
   21,203.28x = 31,806.72 × 5,620.72
4. Step 4: Simplify right side
   21,203.28x = 178,776,667.24
5. Step 5: Solve for x
   x = 178,776,667.24/21,203.28
6. Step 6: Final answer
   x = 8,431.56