Question 106908
Cost to make w wing nuts is 
{{{C=0.07w + 13.3}}}
For w=375, then
{{{C=0.07w + 13.3}}}
{{{C=0.07(375) + 13.3}}}
{{{C=39.55}}}
The cost to make 375 wing nuts is $39.55. 
The average cost is the total cost divided by the total number of wing nuts. 
{{{A=C/375}}}
{{{A=39.55/375}}}
{{{A=0.105}}}
The average cost is about 10.5 cents per wing nut, rounded off.