In: Economics
A Bloomberg BusinessWeek subscriber study asked, "In
the past 12 months, when traveling for business, what type of
airline ticket did you purchase most often?" A second question
asked if the type of airline ticket purchased most often was for
domestic or international travel. Sample data obtained are shown in
the following table.
| Type of Flight | ||
| Type of Ticket | Domestic | International | 
| First Class | 24 | 29 | 
| Business Class | 121 | 98 | 
| Economy Class | 131 | 517 | 
a. Using a .05 level of significance, is the type of ticket purchased independent of the type of flight? Use Table 12.4.
H 0: - Select your answer -Type of ticket purchased is independent of the type of flightType of ticket purchased is not independent of the type of flightItem 1
H a: - Select your answer -Type of ticket
purchased is independent of the type of flightType of ticket
purchased is not independent of the type of flightItem 2
Compute the value of the  2 test statistic (to
2 decimals).
The p-value is Selectless than .005between .005 and
.01between .01 and .025between .025 and .05between .05 and
.10greater than .10Item 4 .
What is your conclusion?
Chi-squared test
| 
 Type of Flight  | 
|||
| 
 Type of Ticket  | 
 Domestic  | 
 International  | 
 Total  | 
| 
 First Class  | 
 24  | 
 29  | 
 53  | 
| 
 Business Class  | 
 121  | 
 98  | 
 219  | 
| 
 Economy Class  | 
 131  | 
 517  | 
 648  | 
| 
 Total  | 
 276  | 
 644  | 
 920  | 
H0: Type of ticket and type of flight are independent
H1: Type of ticket and type of flight are associated
| 
 Expected Number (E) (assuming that H0 is true)  | 
 Observed Number (O)  | 
 (O-E)2/E  | 
|
| 
 First Class & Domestic  | 
 (53×276)/920 = 15.9  | 
 24  | 
 4.13  | 
| 
 Business Class & Domestic  | 
 (219×276)/920 = 65.7  | 
 121  | 
 46.55  | 
| 
 Economy Class & Domestic  | 
 (648×276)/920 = 194  | 
 131  | 
 20.68  | 
| 
 First Class & International  | 
 (53×644)/920 = 37.1  | 
 29  | 
 1.77  | 
| 
 Business Class & International  | 
 (219×644)/920 = 153.3  | 
 98  | 
 19.95  | 
| 
 Economy Class & International  | 
 (648×644)/920 = 453.6  | 
 517  | 
 8.86  | 
| 
 Total  | 
 920  | 
 920  | 
 101.93  | 
Chi-square statistics (calculated) = 101.93
Degree of freedom (df)= (number of rows-1) (number of columns-1) = (3-1) (2-1) = 2
We shall accept the H0 if Chi-square (calculated) is smaller than Chi-square table value at given significance level and df=2 and reject H0 (or accept H1) if Chi-square (calculated) is greater than Chi-square table value at given significance level and df=2.
Chi-squared table value at df=2 and .05 significance level= 7.38
Thus, we shall reject H0 (i.e. accept H1) and conclude that the type of ticket and type of flight are associated.
Since the Chi-square statistics (calculated) is greater than 10.597, the results are significant at .005 level of significance.