The paper presents the results of a study of student engagement in online learning when using a mobile application and a web version of an educational platform. A two-tailed z-test was employed to examine differences in the time spent on the platform by students in the two groups, as a key indicator of student engagement in the educational process. The results of the z-test indicate statistically significant differences between the group of students who used the mobile application and the group using the web version. This suggests that the format of accessing educational materials influences student engagement. The application of the z-test assumes that the data is normally distributed, which was confirmed using the Shapiro-Wilk test. The paper includes a graphical representation of the distribution of time spent on the platform for both groups, as well as a chart comparing the average time spent on the platform for each group. These visualizations complement the results of the z-test and provide a clear assessment of the differences between the groups. The findings of the research have important implications for the development of e-learning courses and online education programs tailored to user preferences.