Finding the Fourth Proportional to 2,099.72, 2,896.88 and 1,391.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,099.72 : 2,896.88 = 1,391.91 : x
2. Step 2: Convert to fraction form
   2,099.72/2,896.88 = 1,391.91/x
3. Step 3: Cross multiply
   2,099.72x = 2,896.88 × 1,391.91
4. Step 4: Simplify right side
   2,099.72x = 4,032,196.24
5. Step 5: Solve for x
   x = 4,032,196.24/2,099.72
6. Step 6: Final answer
   x = 1,920.35