Finding the Fourth Proportional to 10,921.68, 16,384.86 and 3,996

Step by Step Solution

1. Step 1: Write the proportion equation
   10,921.68 : 16,384.86 = 3,996 : x
2. Step 2: Convert to fraction form
   10,921.68/16,384.86 = 3,996/x
3. Step 3: Cross multiply
   10,921.68x = 16,384.86 × 3,996
4. Step 4: Simplify right side
   10,921.68x = 65,473,900.56
5. Step 5: Solve for x
   x = 65,473,900.56/10,921.68
6. Step 6: Final answer
   x = 5,994.86