Finding the Fourth Proportional to 3,640.91, 5,023.59 and 2,128.23

Step by Step Solution

1. Step 1: Write the proportion equation
   3,640.91 : 5,023.59 = 2,128.23 : x
2. Step 2: Convert to fraction form
   3,640.91/5,023.59 = 2,128.23/x
3. Step 3: Cross multiply
   3,640.91x = 5,023.59 × 2,128.23
4. Step 4: Simplify right side
   3,640.91x = 10,691,354.95
5. Step 5: Solve for x
   x = 10,691,354.95/3,640.91
6. Step 6: Final answer
   x = 2,936.46