Finding the Fourth Proportional to 3,900.78, 5,383.05 and 2,308.52

Step by Step Solution

1. Step 1: Write the proportion equation
   3,900.78 : 5,383.05 = 2,308.52 : x
2. Step 2: Convert to fraction form
   3,900.78/5,383.05 = 2,308.52/x
3. Step 3: Cross multiply
   3,900.78x = 5,383.05 × 2,308.52
4. Step 4: Simplify right side
   3,900.78x = 12,426,851.67
5. Step 5: Solve for x
   x = 12,426,851.67/3,900.78
6. Step 6: Final answer
   x = 3,185.74