Finding the Fourth Proportional to 1,806.72, 2,709.12 and 780.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,806.72 : 2,709.12 = 780.48 : x
2. Step 2: Convert to fraction form
   1,806.72/2,709.12 = 780.48/x
3. Step 3: Cross multiply
   1,806.72x = 2,709.12 × 780.48
4. Step 4: Simplify right side
   1,806.72x = 2,114,413.98
5. Step 5: Solve for x
   x = 2,114,413.98/1,806.72
6. Step 6: Final answer
   x = 1,170.31