A, She can buy from 0 to 12 bags, but no more.
The equation for slope between two points is (y1-y2)/x1-x2
Plug the points into the equation
-5-(-10)/-2-3
5/5
m=1
To find the equation, use y-y1=m(x-x1)
y-(-5)=1(x-(-2))
y+5=x+2
y=x+2-5
y=x-3
1) Mean
The mean is given by the sum of the data divided by the number of data (4, in this case):

2) Standard deviation
The standard deviation is given by:

where

is the mean, that we already found at point 1), and N=4. Substituting data, we have:

He lost $30 bc
Guy stole $100
Guy gave back $70
Owner gives hue $30 !
If that makes any sense ♀️