$(3$ points each$)$ Given the figure below, answer the following questions:

a$.$ What is the maximum stress at the $19$ mm diameter hole?

b$.$ What is the stress concentration factor at the $4\mathrm{.}8$ mm radius?

c$.$ Assuming the material for this part is ASTM A$48$ No$30$A Gray Cast Iron and you are using a

Safety Factor of $3\mathrm{.}0,$ what would be the max axial stress allowable at the $4\mathrm{.}8$ mm radius?