To test whether different ways of teaching Statistics decreasing students anxieties about Statistics, a Statistics instructor gave 3 tests to 3 of his different Statistics classes to rate student anxiety at the beginning and end of his course. Anxiety levels were measured on a scale of 1-10 (10 is high anxiety). He then constructed the 95% confidence interval for each classes. Let d = After taking the course anxiety level Before taking the course anxiety level. Class 1:(1.2)less thandless than(.6) Class 2:(1.1)less thandless than(.6) Class 3:(.7) less thandless than(1.2) a) which class shows no change in mean anxiety levels after taking the class. b) which class shows the reduced in mean anxiety levels after taking the class. c) which class shows the increased in mean anxiety levels after taking the class. ( please use words instead of signs and symbols, I don't understand them)