We have gathered a lot of information about our datasets. We know the distribution of the data and their variances. Let's review the histogram, box plot, and violin plot for the 'Impression' column in the control and test groups.

The Shapiro test has provided evidence of normality in the distributions, and the Levene test has provided statistical evidence of homogeneity of variances.

Now it's time to answer the main question: are the mean values of the control and test groups for the 'Impression' column equal?

As you might have guessed, we can use another statistical test for help. The t-test (Student's t-test) is a statistical test used to compare the means of two groups.

It allows us to determine whether there is a statistically significant difference between the mean values of these groups.

The t-test is based on the assumption that the data distribution in each group is normal. It also assumes homogeneity of variances in both groups.