2. An environmental survey contained a question asking what respondents thought was the major cause of air pollution in this country, giving the choices \"automobiles,\" \"factories,\" and \"incinerators.\" Two versions of the test, A and B, were used. Let p4 and pi: be the respective proportions of people using forms A and 3 who select \"factories.\" If 170 out of 460 people who used versionA chose \"factories\" and 141 out of 440 people who used version B chose \"factories,\" a) Find a 95% condence interval for the difference of these two proportions. Interpret the interval in the context of the problem. b) Do the versions seem to be consistent concerning this answer? Why or why not