Question

Nancy, Inc. has three stores located in three different areas. Random samples of the sales of the three stores (in $1000) are shown below. Please note the sample sizes are not equal.

Store 1	Store 2	Store 3
46	34	33
47	36	31
45	35	35
42	39
45

1. Compute the overall mean
2. At a 5% level of significance, test to see if there is a significant difference in the average sales of the three stores.

Answer 1

Run Anova single factor analysis in excel followed by below procedures:

1. Go to data tab --> data analysis --> choose Anova Single Factor

a. Compute the overall mean:

Mean per category:

b)  5% level of significance:

P-value: 0.0000316, lesser than 0.05

If the p-value is less than or equal to the significance level, you reject the null hypothesis and conclude that not all of population means are equal