Finding the Fourth Proportional to 10,928.79, 16,389.16 and 3,906.91

Step by Step Solution

1. Step 1: Write the proportion equation
   10,928.79 : 16,389.16 = 3,906.91 : x
2. Step 2: Convert to fraction form
   10,928.79/16,389.16 = 3,906.91/x
3. Step 3: Cross multiply
   10,928.79x = 16,389.16 × 3,906.91
4. Step 4: Simplify right side
   10,928.79x = 64,030,973.10
5. Step 5: Solve for x
   x = 64,030,973.10/10,928.79
6. Step 6: Final answer
   x = 5,858.93