A large advertising firm specializes in creating television commercials for children’s p...

A large advertising firm specializes in creating television commercials for children’s products. The firm wants to design a study to investigate factors that may affect the length of time a commercial is able to hold a child’s attention. A preliminary study determines that two factors that may be important are the age of the child and the type of product being advertised. The firm wants to determine whether there were large differences in the mean length of time that the commercial is able to hold the child’s attention depending on these two factors. If there proves to be a difference, the firm would then attempt to determine new types of commercials depending on the product and targeted age group. Three age groups are used:

The types of products selected are

A group of 30 children is recruited in each age group and 10 are randomly assigned to watch a 60-second commercial for each of the two products. Researchers record their attention span during the viewing of the commercial. The data are given here.

Mean by age group: Mean by product type:

a. Identify the design.

b. Write a model for this situation, identifying all the terms in the model.

c. Estimate the parameters in the model.

d. Compute the sum of squares for the data and summarize the information in an AOV table.