Finding the Fourth Proportional to 3,413.78, 5,123.10 and 1,856.96

Step by Step Solution

1. Step 1: Write the proportion equation
   3,413.78 : 5,123.10 = 1,856.96 : x
2. Step 2: Convert to fraction form
   3,413.78/5,123.10 = 1,856.96/x
3. Step 3: Cross multiply
   3,413.78x = 5,123.10 × 1,856.96
4. Step 4: Simplify right side
   3,413.78x = 9,513,391.78
5. Step 5: Solve for x
   x = 9,513,391.78/3,413.78
6. Step 6: Final answer
   x = 2,786.76