165\15= number of tubs
165 divided by 15 equals the amount of the tubs that he sold.
(I assume the two different name things, isaac&dominic, is a mistake since there isnt any information for Dominic)
20.5 is the IQR of the given set of numbers.
Well to find this line you want to know the slope and the y-intercept. So find the slope:
(y2-y1)/(x2-x1)
12-2 = 10
2-7 = -5
10/-5 = 2/-1
-2 is your slope
Now for y-intercept, find the point closest to the y-axis. That is the point (2,12), and if your slope is negative 2, that means that if you go up 4 and left 2, you should find the y-intercept:
12 + 4 = 16
16 is your y-intercept
So now lets write this out in an equation:
y = mx + b
m = slope
b = y-intercept
y = -2x + 16
there you go! hope this helps!