Answer:
ok so first you add all the prices together.
$9:00+$7:00+$8:00+$6:00+$4:00=34
then divide 34 by the number of prices.
34/5
then you get the mean
$6.8 is the mean
Step-by-step explanation:
 
        
             
        
        
        
or, x=180
or,34=180
or,180-34
or x=146
Now,
 or, y=146
or,18=146
or146-18
 or, y=128
there is x is 34 and its all side angle is 180 degree So put x =180 and then put x value is 34 =180 and there is no values in front of 34 so there will be + and if +so in another side it will be - and then after put 180-34=146
 
        
             
        
        
        
569/x=100/18
multiply both sides of the equation
569=5.55556
now we divide 
569/5.55556
102.42=x
18% of 569=102.42