Finding the Fourth Proportional to 3,856.30, 5,321.69 and 2,087.91

Step by Step Solution

1. Step 1: Write the proportion equation
   3,856.30 : 5,321.69 = 2,087.91 : x
2. Step 2: Convert to fraction form
   3,856.30/5,321.69 = 2,087.91/x
3. Step 3: Cross multiply
   3,856.30x = 5,321.69 × 2,087.91
4. Step 4: Simplify right side
   3,856.30x = 11,111,172.72
5. Step 5: Solve for x
   x = 11,111,172.72/3,856.30
6. Step 6: Final answer
   x = 2,881.30