we are given
![C(x)=200+10x+0.2x^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/okkq0alos7lqnky7erctl9sdn6u37n3jx1.png)
part-A:
Since, x is number of tablets
C(x) is cost of producing x tablets
so, vertical box is C(x)
so, we write in vertical box is "cost of producing x tablets"
Horizontal box is x
so, we write in horizontal box is "number of tablets"
part-B:
we have to find average on [a,b]
we can use formula
![(C(b)-C(a))/(b-a)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/4sx4mugawocxmv6s7zpkrwsxtp3thfh8pw.png)
we are given point as
a: (15 , 395)
a=15 and C(15)=395
b: (20, 480)
b=20 , C(20)=480
now, we can plug values
![=(480-395)/(20-15)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/oyrwi9twu5z4gc6yplbykndgob9aktbk79.png)
...........Answer
part-c:
we have to find average on [b,c]
we can use formula
![(C(c)-C(b))/(c-b)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/jqeo1fvxje9jy714l9cn30r73xvyy9avk6.png)
we are given point as
b: (20, 480)
b=20 , C(20)=480
c:(25,575)
c=25 , C(c)=575
now, we can plug values
![=(575-480)/(25-20)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/7q1x4oo8ps9gea8n5n0j74mwusuj5u18x4.png)
..............Answer