Its not A and its not D. Its B or C. I think its C. 
I hope this helped.
        
                    
             
        
        
        
Answer:
a) square root of 11
Step-by-step explanation:
by taking the distance between each x and y that equals 7 and 4 so you put that under a square root, add them and it equals the square root of 11
 
        
             
        
        
        
Answer:
1:4
Step-by-step explanation:
If 8/10 prefer Crest, that means 2/10 don't prefer it.
To find the ratio, put together the number that don't prefer it to the number that does:
2:8
Simplify by dividing each side by 2:
1:4
So, the ratio is 1:4
 
        
             
        
        
        
To find the slope of a line that goes through given points with known coordinates, you divide the subtraction of the y of the second point minus the y of the first point, by the subtraction of the x of the second point minus the x of the first point:
m = (yB-yA) / (xB-xA)
Let A(8,5) and B(6,7).
With yB = 7; yA = 5; xB = 6; xA = 8
m = (7-5) / (6-8)
m = 2/-2
m = -1
So the slope of the line that goes through the given points (8,5) and (6,7) is m = -1.
I've added a pic of the line with both points under the answer.
Hope this Helps! :)
 
        
             
        
        
        
Answer:
in total there are 80 subjects. I don't know what class width is though. 
Step-by-step explanation:
Look at the graph