Finding the Fourth Proportional to 21,215.79, 31,823.33 and 7,172.82

Step by Step Solution

1. Step 1: Write the proportion equation
   21,215.79 : 31,823.33 = 7,172.82 : x
2. Step 2: Convert to fraction form
   21,215.79/31,823.33 = 7,172.82/x
3. Step 3: Cross multiply
   21,215.79x = 31,823.33 × 7,172.82
4. Step 4: Simplify right side
   21,215.79x = 228,262,982.03
5. Step 5: Solve for x
   x = 228,262,982.03/21,215.79
6. Step 6: Final answer
   x = 10,759.11