A 90% confidence interval and a 96% confidence interval are computed from the same set of data. Which of the following statements is correct?
       |       | a. The intervals have the same  width. |  |  | 
    |       | b. The 90% confidence interval is  wider. |  |  | 
    |       | c. The 96% confidence interval is  wider. |  |  | 
    |       | d. You need to know the sample  size, n, and the standard deviation to determine which  interval is wider. |  |  | 
    
96% confidence interval is wider than 90% confidence interval because in 96% we include more pausible values than in 90% confidnce interval. So statement (a) and (b) are false.
 And statement (c) is correct.