Finding the Fourth Proportional to 13,320.72, 19,981.20 and 3,960.84

Step by Step Solution

1. Step 1: Write the proportion equation
   13,320.72 : 19,981.20 = 3,960.84 : x
2. Step 2: Convert to fraction form
   13,320.72/19,981.20 = 3,960.84/x
3. Step 3: Cross multiply
   13,320.72x = 19,981.20 × 3,960.84
4. Step 4: Simplify right side
   13,320.72x = 79,142,336.21
5. Step 5: Solve for x
   x = 79,142,336.21/13,320.72
6. Step 6: Final answer
   x = 5,941.30