CosA=(21^2+23^2-25^2)/2*21*23
cosA=345/966
A=cos^-1(345/966)
A=69.08
Answer:
Mean: 29.5; Median: 26; Modes: 25, 26
Step-by-step explanation:
Add 10+12+25+25+26+26+30+31+33+34+47+55 = 354
Then divide it by 12 354/12 = 29.5
Mode are numbers that appear most often which in this case are 2 numbers, 25 and 26.
So we will be using
form, in which m = slope and b = y-intercept. Since we know the slope (-8), all we need to do is solve for the y-intercept. We can do this by inserting (-2,2) into the equation and solve for b.

Firstly, do the multiplication: 
Next, subtract 16 on both sides, and your answer will be -14 = b
Using the previous info we have, our equation is y = -8x - 14