Does the interval found in part ( a) contain numbers that are all positive? all negative? mixed? Comment on the meaning of the confidence interval in the context of this problem. At the 90% level, do you detect any differences in the proportion of accurate responses to the question from face- to- face inter-views as compared with the proportion of accurate responses from telephone interviews? ( c) Test the claim that there is a difference in the proportion of accurate responses from face- to- face interviews compared with the proportion of accurate responses from telephone interviews. Use a = 0.05.