First, we learned the one-sided versions of the one-sample T-test (see the first two pages of the classroom notes above), and we tried them in R on the cholesterol data. Then we continued the conversion of the first version of the cholesterol data (we started it in the previous class). After that, we learned the paired two-sample and independent two-sample T-tests (see the third page of the classroom notes above). Finally using these tests, we answered the questions found in the third page of the classroom notes above in terms of the expectations. In both cases we rejected the null hypothesis (the p-values were small, smaller than, say, 0.05), hence, also using the fact that the performed two-sided tests test both directions simultaneously, and also taking into account the averages, we concluded that the day 14 cholesterol of patients is significantly less than their day 2 cholesterol, however, it is significantly larger than the healthy cholesterol. I note that in R the Welch's version of the independent two-sample T-test is performed by default, to run the classical version the setting "var.equal = TRUE" is needed.