For the following exercise, assume that all the assumptions required to apply the one-way ANOVA procedure hold true. A clothing store chain is having a sale based on the use of a coupon. The company is interested in knowing whether the wording of the coupon affects the number of units of the product purchased by customers. The company created four coupons for the same product, each with different wording. Four groups of 50 customers each were selected at random. Group 1 received the first version of the coupon, Group 2 received the second version, and so on. The units of the product purchased by each customer were recorded.
The following ANOVA table contains some of the values from the analysis. Assume that the four populations are normally distributed with equal variances. Find the missing values and complete the ANOVA table. Round your answers to three decimal places if required.
Source of Variation
Degrees of Freedom
Sum of Squares
Mean Square
Value of the Test Statistic
Between
Within
74910.580
Total
77665.713
What are the appropriate null and alternative hypotheses for this analysis?
Ho: Not all four population means are equal. Ha: All four population means are equal.
Ho: Not all four population means are equal. Ha: All four population means are different from each other.
Ho: All four population means are equal. Ha: Not all four population means are equal.
Ho: All four population means are equal. Ha: All four population means are different from each other.
Using a significance level of 0.05, what is your conclusion about the equality of population means for all four coupons?
Because the value of the test statistic is less than the critical value of F, we reject the null hypothesis.