Example of ANOVA and interpretation
Decision One: ANOVA
Deb is contemplating three new locations for her pizza business – adjacent to campuses in Portland, Eugene, and Salem A random survey of 27 pizza shops in those locations is conducted with 9 stores surveyed in each location. (Deb hired college students to sit in the stores and eavesdrop on the pizza ordering clerk). The number of pizzas sold per hour was tallied and the students then computed the sales volume in actual dollars. Deb wants to know if there is a significant difference in location.
a) What are the null and alternate hypotheses?
b) What are the degrees of freedom for the numerator and denominator?
c) What is the critical value of F at the 5% level of significance?
d) What is the mean square for treatments?
e) What is the computed value of F?
f) What is your decision?
Attach your answers to these questions to the business memo.
If you find a significant difference, construct 95% confidence intervals in order to determine which location(s) might be different. Your recommendation to Deb should include the location(s) where she can expect the optimum sales.
Portland Eugene Salem
132.30 123.15 128.55
138.90 99.75 127.50
130.50 111.60 136.65
134.55 119.25 123.00
129.60 123.00 124.80
124.35 116.25 118.20
141.75 132.60 148.50
141.30 126.00 141.45
138.75 119.70 132.75