About one student per week joined the new recordbuying coop. the members wanted to increase membership, so the coop decided to try a newspaper advertisement, after which about 20 students per week joi

About one student per week joined the new recordbuying coop. the members wanted to increase membership, so the coop decided to try a newspaper advertisement, after which about 20 students per week joined the coop. the members concluded that the advertising campaign (treatment) was effective because the ad succeeded in getting new members. should the members be confident that advertising increased their results