In: Statistics and Probability
You want to study an agricultural treatment to remove a pest on citrus plants. Suppose you have a citrus farm. The presence of the pest is measured by the productivity of the plant. Suppose that before and after applying the treatment the productivity of 9 plants was measured. Measurements are in numbers of bags and are in the following table:
Find the confidence interval to see if there is an improvement in productivity with the treatment of the pest. Determine with 95% confidence the interval for the average difference in citrus productivity.
| 
 Before  | 
 35  | 
 28  | 
 33  | 
 42  | 
 38  | 
 43  | 
 36  | 
 26  | 
 35  | 
| 
 After  | 
 38  | 
 33  | 
 37  | 
 41  | 
 40  | 
 44  | 
 39  | 
 28  | 
 39  |