Finding the Fourth Proportional to 3,953.56, 5,455.86 and 2,185.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,953.56 : 5,455.86 = 2,185.20 : x
2. Step 2: Convert to fraction form
   3,953.56/5,455.86 = 2,185.20/x
3. Step 3: Cross multiply
   3,953.56x = 5,455.86 × 2,185.20
4. Step 4: Simplify right side
   3,953.56x = 11,922,145.27
5. Step 5: Solve for x
   x = 11,922,145.27/3,953.56
6. Step 6: Final answer
   x = 3,015.55