Given the table, we want to calculate the probability of choosing a female student, given that it is a junior. Since we are conditioned that the student is a junior, we can forget all the table data excep for the column that says "junior"
For this column, we have that 2 students are male and 6 are female. That is, we have a total of 8 students.
Now, we want to calculate the probability. To do so, we simply divide the total number of possibilites such that the event "choosing a female" is true by the total number of people.
Since we have 6 female students, we have 6 possibilites of choosing a female. So the probability would be
[tex]\frac{6}{8}=\frac{2\cdot3}{2\cdot4}=\frac{3}{4}=0.75[/tex]
To express it as a percentage, we simply multiply it by 100. So we get
[tex]0.75\cdot100=75[/tex]
