(7) (3 pts) Let $A_j$ represent the amount of algae in kilograms ($kg$) removed from a lake on the $j^{th}$ day of the year in 2022, for $j \ge 1$. Using sigma notation, represent the total amount of algae (in $kg$) removed as one sum during the months January (31 days), February (28 days), and March (31 days) of 2022.
