Suppose:

grades is a $505$ array that holds grades for a class of $50$ students for $5$ different labs gender is a $50$ element column vector holding a gender designation $(\text{'}$male$\text{'}$ or 'female'$)$ for each member in the class

age is a $50$ element column vector holding the ages of the class members

level is a $50$ element column vector holding a number corresponding to their college level freshman