Suppose the following data were obtained in an environmental to study concerning the manufacture of cakes which should be_ insensitive the temperature. T and the time t of baking. The cake mix employed different amounts of flour F, shortening, and egg powder E. The factors where vaned at two levels denoted by - and + in a factorial design with an intem1ediate value denoted by 0. The data are average scores of an hedonic index scaled from I to· 7 as judged by a taste panel.
(a) What are the design factors?
(b) What are the environmental factors?
(c) Calculate the average y and standard deviation y for each of the nine designs (recipes). What do you conclude from your analysis?