D(7, 3), E(8, 1), and F(4, -1)
We calculate the squared distances between the points:



Since
we have a right triangle with hypotenuse DF.
Answer: 54 mph
Step-by-step explanation:
d-the distance
s+9 - the speed to the conference
d=6*(s+9)
s- is the speed on the way back home
d=7*s
so 6*(s+9)=7*s
6s+54=7s
-6s -6s
54= 7s-6s
s=54 mph
\left[x \right] = \left[ 16+3\,y\right][x]=[16+3y] totally graphic doing ur sheets
For the mean you add them all up and divide by the ammount of numbers you added. So it would be 118