A consumer advocate examines whether the longevity of car batteries (measured in years) is affected by the b rand name (factor A) and whether or not the car is kept in a garage (factor B). Interaction is suspected. The results are shown in the accompanying tab le and are also available on the text website, labeled B rand and Garage.
a. Use Excel to generate the appropriate ANOVA.
b. At the 5 % significance level, is there interaction between brand name and whether a car is garaged?
c. At the 5 % significance level, can you conclude that average battery lives differ by brand name?
d. At the 5 % significance level, can you conclude that average battery lives differ depending on whether a car is garaged?