Finding the Fourth Proportional to 13,981.69, 20,976.18 and 5,216.68

Step by Step Solution

1. Step 1: Write the proportion equation
   13,981.69 : 20,976.18 = 5,216.68 : x
2. Step 2: Convert to fraction form
   13,981.69/20,976.18 = 5,216.68/x
3. Step 3: Cross multiply
   13,981.69x = 20,976.18 × 5,216.68
4. Step 4: Simplify right side
   13,981.69x = 109,426,018.68
5. Step 5: Solve for x
   x = 109,426,018.68/13,981.69
6. Step 6: Final answer
   x = 7,826.38