Finding the Fourth Proportional to 13,215, 19,823.22 and 3,981.72

Step by Step Solution

1. Step 1: Write the proportion equation
   13,215 : 19,823.22 = 3,981.72 : x
2. Step 2: Convert to fraction form
   13,215/19,823.22 = 3,981.72/x
3. Step 3: Cross multiply
   13,215x = 19,823.22 × 3,981.72
4. Step 4: Simplify right side
   13,215x = 78,930,511.54
5. Step 5: Solve for x
   x = 78,930,511.54/13,215
6. Step 6: Final answer
   x = 5,972.80