Finding the Fourth Proportional to 3,933.89, 5,428.79 and 2,255.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,933.89 : 5,428.79 = 2,255.40 : x
2. Step 2: Convert to fraction form
   3,933.89/5,428.79 = 2,255.40/x
3. Step 3: Cross multiply
   3,933.89x = 5,428.79 × 2,255.40
4. Step 4: Simplify right side
   3,933.89x = 12,244,098.60
5. Step 5: Solve for x
   x = 12,244,098.60/3,933.89
6. Step 6: Final answer
   x = 3,112.46