A group of 40 subjects was divided into two groups with one group given an energy drink and one group given water. The subjects were then given a spelling test and the mean number of words correctly spelled was recorded for each member of the two groups. This experiment was designed this way to quantify which of the following types of variability?

Do social recommendations increase ad effectiveness? a study of online video viewers compared viewers who arrived at an advertising video for a particular brand by following a social media recommendation link to viewers who arrived at the same video by web browsing. data were collected on whether the viewer could correctly recall the brand being advertised after seeing the video. the results are given below.correctly recalled the brandarrival 409153browsing20484b. conduct the hypothesis test, using the 0.025 level of significance.what is the value of the test statistic? χ2stat=what is the p-value? p-value=is this value significant atα=0.025?