In: Statistics and Probability
According to an article in Marketing News, fewer checks are being written at the grocery store checkout than in the past. To determine whether there is a difference in the proportion of shoppers who pay by check among three consecutive years at a 0.01 level of significance, the results of a survey of 500 shoppers in three consecutive years are obtained and presented below.
| 
 Check Written  | 
 YEAR  | 
||
| 
 YEAR 1  | 
 YEAR 2  | 
 YEAR 3  | 
|
| 
 YES  | 
 230  | 
 170  | 
 140  | 
| 
 NO  | 
 270  | 
 330  | 
 360  | 
1=
What is the form of the null hypothesis?
| 
 H0:π1 = π2 ≠ π3  | 
||
| 
 H0 :π1 ≠π2 ≠π3  | 
||
| 
 H0:π1= π2 = π3  | 
||
| 
 H0 :π1 ≠π2 = π3  | 
2= what is the critical value ?
3=what is the value of the test statistic?