A clothing manufacturer would like to determine whether celebrity endorsements and length of commercial influence a customer's decision to buy its products. In order to estimate this potential influence, the manufacturer premieres its latest series of commercials privately to potential buyers. There are two types of commercials: commercials without celebrities, and commercials with celebrities. There are two lengths of commercials: 30 seconds and 60 seconds. Each potential buyer is randomly assigned a type and length of commercial to view. What are the factors of interest to the manufacturer