Penningtons Superstore specializes in plus$-$size fashions for women. It was considering adding a line of teen plus sizes to its stores. Before doing so$,$ it contracted with a marketing research firm to make sure that the teen plus$-$size market was a viable one. Decision makers needed the results of its study by September $15$ so Penningtons could introduce the line the following March, if the market was viable. The major constraint for research here is