Finding the Fourth Proportional to 10,931.19, 16,400.24 and 3,911.05

Step by Step Solution

1. Step 1: Write the proportion equation
   10,931.19 : 16,400.24 = 3,911.05 : x
2. Step 2: Convert to fraction form
   10,931.19/16,400.24 = 3,911.05/x
3. Step 3: Cross multiply
   10,931.19x = 16,400.24 × 3,911.05
4. Step 4: Simplify right side
   10,931.19x = 64,142,076.65
5. Step 5: Solve for x
   x = 64,142,076.65/10,931.19
6. Step 6: Final answer
   x = 5,867.81