Finding the Fourth Proportional to 3,899.42, 5,381.18 and 2,131.02

Step by Step Solution

1. Step 1: Write the proportion equation
   3,899.42 : 5,381.18 = 2,131.02 : x
2. Step 2: Convert to fraction form
   3,899.42/5,381.18 = 2,131.02/x
3. Step 3: Cross multiply
   3,899.42x = 5,381.18 × 2,131.02
4. Step 4: Simplify right side
   3,899.42x = 11,467,399.54
5. Step 5: Solve for x
   x = 11,467,399.54/3,899.42
6. Step 6: Final answer
   x = 2,940.80