Finding the Fourth Proportional to 3,891.51, 5,370.18 and 2,123.10

Step by Step Solution

1. Step 1: Write the proportion equation
   3,891.51 : 5,370.18 = 2,123.10 : x
2. Step 2: Convert to fraction form
   3,891.51/5,370.18 = 2,123.10/x
3. Step 3: Cross multiply
   3,891.51x = 5,370.18 × 2,123.10
4. Step 4: Simplify right side
   3,891.51x = 11,401,429.16
5. Step 5: Solve for x
   x = 11,401,429.16/3,891.51
6. Step 6: Final answer
   x = 2,929.82