A marketing research firm wants to determine the most effective method of selling furniture: print, radio, television, or online. They recruit 310 volunteers to participate in the study. The researcher segments the volunteers by level of income. Of the 310 volunteers, 80 earn below $ 20 comma 000, 60 earn between $ 20 comma 000 and $ 40 comma 000, 110 earn between $ 40 comma 000 and $ 60 comma 000, and 60 earn over $ 60 comma 000. The volunteers from each group are randomly assigned to either the print advertising group, the radio group, the television group, or the online group. Each group is exposed to the advertising. After 3 hours, a recall exam is given with the proportion of correct answers recorded. What type of experimental design is this?a. Matched pairb. Randomized block designc. Surveyd. Completely randomized assignmentWhat is the response variable in this experiment?a. The scores on the recall examb. The scores on the pretestc. The ages of the subjectsd. The type of advertisingWhat explanatory variable is manipulated?a. The time before recall examb. The type of advertising

A randomized block design, when conducting an experimental type of research, consists on dividing the whole population into subgroups, also denominated blocks. There is less dispersion in the characteristics of subjects within a block than between blocks. Subsequently, the members of each block are randomly assigned to certain treatments which, in this case, are the different types of advertising to which consumers are exposed.

Question 2

The correct answer is: "The scores on the recall exam".

The aim is to measure the effect of the different advertising campaigns by measuring the subsequent reactions of the participants, which in this case is measured through the recall exam that subjects undertake right after the treatment. Therefore the scores on the recall exam constitute the response or dependent variable that the research aims to explain.

Question 3

The correct answer is: "The type of advertising"

The study aims to quantify the differences registered in the dependent variable, the scores in the recall exams, when subjects have been exposed to different advertising campaings. Therefore the type of advertising constitutes the explanatory variable, whose effect on the dependent variables tries to be assessed.