Finding the Fourth Proportional to 3,899.71, 5,381.59 and 2,131.32

Step by Step Solution

1. Step 1: Write the proportion equation
   3,899.71 : 5,381.59 = 2,131.32 : x
2. Step 2: Convert to fraction form
   3,899.71/5,381.59 = 2,131.32/x
3. Step 3: Cross multiply
   3,899.71x = 5,381.59 × 2,131.32
4. Step 4: Simplify right side
   3,899.71x = 11,469,876.94
5. Step 5: Solve for x
   x = 11,469,876.94/3,899.71
6. Step 6: Final answer
   x = 2,941.21