Finding the Fourth Proportional to 3,939.36, 5,910.72 and 2,090.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,939.36 : 5,910.72 = 2,090.40 : x
2. Step 2: Convert to fraction form
   3,939.36/5,910.72 = 2,090.40/x
3. Step 3: Cross multiply
   3,939.36x = 5,910.72 × 2,090.40
4. Step 4: Simplify right side
   3,939.36x = 12,355,769.09
5. Step 5: Solve for x
   x = 12,355,769.09/3,939.36
6. Step 6: Final answer
   x = 3,136.49