You work for an advertising agency that is preparing a new television commercial to appeal to women. You have been asked to design an experiment to compare the effectiveness of three versions of the commercial. Each subject will be shown one of the three versions and then asked about her attitude toward the product. You think there may be large differences between women who are employed and those who are not. Because of these differences, you should use

(a) a block design, but not a matched pairs design

(b) a completely randomized design.

(c) a matched pairs design.

(d) a simple random sample.

(e) a stratified random sample.

The phrase commercial refers to widespread business activity or commerce. A trading firm engaged in business activities that are hedged by bets in the futures or options markets is referred to as a commercial in the investment world.

The organisation inquires as to which design you would prefer to utilise. Immediately notice that d and e are not designs, but rather sampling approaches that can be removed.

When there are just two levels of therapy, a matched pair design is used (treatment is the variable of interest - $3$different versions of TV shows). As a result, it isn't a matched-pair design.

A completely randomised design and the randomised block design are the final two options. Only one treatment component is considered in a completely randomised design. A treatment factor and a blocking factor are both considered in a randomised block design (reminder that the blocking factor is controlling for a nuisance variable like if the experimental unit is employed or not).

Since this design wants to consider that, the answer is randomized block design.