Finding the Fourth Proportional to 2,815.55, 3,864.01 and 2,591.99

Step by Step Solution

1. Step 1: Write the proportion equation
   2,815.55 : 3,864.01 = 2,591.99 : x
2. Step 2: Convert to fraction form
   2,815.55/3,864.01 = 2,591.99/x
3. Step 3: Cross multiply
   2,815.55x = 3,864.01 × 2,591.99
4. Step 4: Simplify right side
   2,815.55x = 10,015,475.28
5. Step 5: Solve for x
   x = 10,015,475.28/2,815.55
6. Step 6: Final answer
   x = 3,557.20