Finding the Fourth Proportional to 5,390.79, 8,086.49 and 2,103.60

Step by Step Solution

1. Step 1: Write the proportion equation
   5,390.79 : 8,086.49 = 2,103.60 : x
2. Step 2: Convert to fraction form
   5,390.79/8,086.49 = 2,103.60/x
3. Step 3: Cross multiply
   5,390.79x = 8,086.49 × 2,103.60
4. Step 4: Simplify right side
   5,390.79x = 17,010,729.85
5. Step 5: Solve for x
   x = 17,010,729.85/5,390.79
6. Step 6: Final answer
   x = 3,155.52