Finding the Fourth Proportional to 3,891.90, 5,370.82 and 2,123.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,891.90 : 5,370.82 = 2,123.50 : x
2. Step 2: Convert to fraction form
   3,891.90/5,370.82 = 2,123.50/x
3. Step 3: Cross multiply
   3,891.90x = 5,370.82 × 2,123.50
4. Step 4: Simplify right side
   3,891.90x = 11,404,936.27
5. Step 5: Solve for x
   x = 11,404,936.27/3,891.90
6. Step 6: Final answer
   x = 2,930.43