Finding the Fourth Proportional to 3,891.57, 5,369.98 and 2,123.16

Step by Step Solution

1. Step 1: Write the proportion equation
   3,891.57 : 5,369.98 = 2,123.16 : x
2. Step 2: Convert to fraction form
   3,891.57/5,369.98 = 2,123.16/x
3. Step 3: Cross multiply
   3,891.57x = 5,369.98 × 2,123.16
4. Step 4: Simplify right side
   3,891.57x = 11,401,326.74
5. Step 5: Solve for x
   x = 11,401,326.74/3,891.57
6. Step 6: Final answer
   x = 2,929.75