Finding the Fourth Proportional to 3,891.72, 5,370.43 and 2,123.29

Step by Step Solution

1. Step 1: Write the proportion equation
   3,891.72 : 5,370.43 = 2,123.29 : x
2. Step 2: Convert to fraction form
   3,891.72/5,370.43 = 2,123.29/x
3. Step 3: Cross multiply
   3,891.72x = 5,370.43 × 2,123.29
4. Step 4: Simplify right side
   3,891.72x = 11,402,980.31
5. Step 5: Solve for x
   x = 11,402,980.31/3,891.72
6. Step 6: Final answer
   x = 2,930.06