Samples of six different brands of diet or imitation margarine were analyzed to determine the level of physiologically active polyunsaturated fatty acids (PAPUFA, in percent), resulting in the data shown in the accompanying table. (The data are fictitious, but the sample means agree with data reported in Consumer Reports.) Imperial 14.1 13.6 14.4 14.3 Parkay 12.8 12.5 13.4 13.0 12.3 Blue Bonnet 13.5 13.4 14.1 14.3 Chiffon 13.2 12.7 12.6 13.9 Mazola 16.8 17.2 16.4 17.3 18.0 Fleischmanns 18.1 17.2 18.7 18.4 a. Test for differences among the true average PAPUFA percentages for the different brands. Use a .05. b. Use the TK procedure to compute 95% simultaneous confidence intervals for all differences between means and interpret the resulting intervals.
Summarizing Data Stats are numbers measured for some purpose Stats is a collection of procedures and principles for gathering data to help people make decisions Methods that are used to analyze data Variable: characteristic that differs from one individual to next Sample data: collected from subset of a larger popul population data: collected when all individuals Statistic a summary measure of sample data Parameter: a summary measure of population data Categorical/ qualitative variable: you can’t find the average One that takes subject and puts it in category ● When a categorical variable has ordered categories, it is called an ordinal variable ○ Has to be fixed though (like s,m,l not typical classroom seat location front, mi