Global Engineers Hired the Following Number of Class 1 Engineers

Global Engineers hired the following number of Class 1 engineers during the first six months of the past year.(Assume the data represents a sample.)
​ $\begin{array}{ll} & {\text { No. of Class 1 }} \\\text { Month } & \text { Engineers Hired } \\\text { January } & 3 \\\text { February } & 2 \\\text { March } & 4 \\\text { April } & 2 \\\text { May } & 6 \\\text { June } & 0\end{array}$ ​
a.
Determine the mean, the median, the mode, and the range for the above data.
b.
Compute the variance and the standard deviation.
c.
Compute the first and the third quartiles.
d.
Compute the z-scores for the months of May and June.