Finding the Fourth Proportional to 2,640.72, 3,643.83 and 1,521.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,640.72 : 3,643.83 = 1,521.57 : x
2. Step 2: Convert to fraction form
   2,640.72/3,643.83 = 1,521.57/x
3. Step 3: Cross multiply
   2,640.72x = 3,643.83 × 1,521.57
4. Step 4: Simplify right side
   2,640.72x = 5,544,342.41
5. Step 5: Solve for x
   x = 5,544,342.41/2,640.72
6. Step 6: Final answer
   x = 2,099.56