Step-by-step explanation
We first need to fill all the values in the table, by adding the terms in the corresponding total boxes, as shown as follows:
Then, if we need to know the number of students that are junior, we must divide the total of the junior column with the total number of students, as follows:
Therefore, P(Junior) = 8/30 = 4/15 = 0.2666
Expressing as a percentage and rounding to the nearest whole number:
P(Junior) = 27%