We know that
Mean and median both try to measure the central tendency in a data set.The mean is commonly used, but sometimes the median is preferred.
Mode is the element which occurs the most times in the set
therefore
the answer is the option 
Both the mean and median are appropriate measures of center.
        
                    
             
        
        
        
Answer:
x=− 9
/4
or  
 =−2.250
Step-by-step explanation:
 
        
             
        
        
        
Answer:
4/12 simplified to 1/3 of rolling 2 times. 
Step-by-step explanation:
 
        
             
        
        
        
1.
If no changes are made, the school has a revenue of :
625*400$/student=250,000$
2.
Assume that the school decides to reduce n*20$.
This means that there will be an increase of 50n students.
Thus there are 625 + 50n students, each paying 400-20n dollars.
The revenue is: 
(625 + 50n)*(400-20n)=12.5(50+n)*20(20-n)=250(n+50)(20-n)
3.
check the options that we have, 
a fee of $380 means that n=1, thus 
250(n+50)(20-n)=250(1+50)(20-1)=242,250   ($)
a fee of $320 means that n=4, thus
 250(n+50)(20-n)=250(4+50)(20-4)=216,000    ($)
the other options cannot be considered since neither 400-275, nor 400-325 are multiples of 20.
Conclusion, neither of the possible choices should be applied, since they will reduce the revenue.
        
             
        
        
        
Answer: 165 secs
Step-by-step explanation:
2 mins has 120 secs in it 
120 + 45 = 165