Finding the Fourth Proportional to 3,919.78, 5,413.60 and 3,675.57

Step by Step Solution

1. Step 1: Write the proportion equation
   3,919.78 : 5,413.60 = 3,675.57 : x
2. Step 2: Convert to fraction form
   3,919.78/5,413.60 = 3,675.57/x
3. Step 3: Cross multiply
   3,919.78x = 5,413.60 × 3,675.57
4. Step 4: Simplify right side
   3,919.78x = 19,898,065.75
5. Step 5: Solve for x
   x = 19,898,065.75/3,919.78
6. Step 6: Final answer
   x = 5,076.32