Question: Blissymbols are pictographs sometimes used to help learn-disabled children. In a study of computer –assisted learning,12 normal-ability school children were assigned at random to each four computer learning programs. After they used the program, they attempted to recognize 24 Blissymbols. Here are the counts correct for one of the programs

12 22 9 14 20 15 9 10 11 11 15 6

(a) Make a stemplot. Are there outliers or strong skewness that would forbid use of the t-procedures?

(b) Give a 90% confidence interval for the mean count correct.