The following data represent the represent the flight timein
     The following data represent the represent the flight time(in minutes) of a random sample of flights from Chicago . Illinois to Atlanta, Georgia on Sounthwest Airlines. 100, 90, 96, 104, 92, 98, 105, 90, 85, 90 Compute the following measures of thye flight time mean median variance
 
  
  Solution
Ordering the data,
85
 90
 90
 90
 92
 96
 98
 100
 104
 105
a)
Getting the mean, X,      
       
 X = Sum(x) / n      
 Summing the items, Sum(x) =    950  
 As n =    10  
 Thus,      
 X =    95   [ANSWER, MEAN]
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b)
The median is the mean of the two middle terms (5th and 6th)
Median = (92+96)/2 = 94 [ANSWER]
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c)
Setting up tables,          
 x   x - X   (x - X)^2  
 85   -10   100  
 90   -5   25  
 90   -5   25  
 90   -5   25  
 92   -3   9  
 96   1   1  
 98   3   9  
 100   5   25  
 104   9   81  
 105   10   100  
           
 Thus, Sum(x - X)^2 =    400      
           
 Thus, as           
           
 s^2 = Sum(x - X)^2 / (n - 1)          
           
 As n =    10      
           
 s^2 =    44.44444444   [ANSWER, VARIANCE]  


