Laboratory experiment, ANOVA : Recall the laboratory experiment described in Exercise 13.2. The response variable is weight gains (in grams). There are three groups of lab animals, each with five test animals. Data are shown in Table 13.4.

a). find one-way analysis of variance for this problem. Show all hypothesis testing steps, and interpret the results.

TABLE 13.4 Weight gain over a 1-month period (grams) in lab mice :

group 1 (standard) : 9.09 , 9.96 , 9.72 , 9.64 , 8.14

group 2 (junk food): 10.21 , 10.48 , 13.01 , 12.74 , 12.58

group 3 (organic): 9.03 , 9.55 , 12.35 , 9.33 , 9.51

Data were generated with a random number generator so that X1 ~ N(10,1), X2 ~ (12,1), and X3 ~ N(10,1).