We wanted to understand the relationship between a country’s economic status (as indicated by its income group) and its confirmed cases at the time of closure. Since one is a categorical variable and another is a numerical variable, we decided to use a boxplot with dots to visualize the distribution. We included the sample sizes, mean, and interquartile range under the box plot to have a numerical understanding of our data with different income levels. 

 

We wanted to understand if different income levels affect a country’s access to online education. Since we have two categorical variables, we created a 2x2 contingency table. Since different income levels have different numbers of countries, we decided to use percentages instead of the actual numbers to display the contingency table. This gives us a more realistic and intuitive understanding of countries’ implementation of online education.

 

In addition to the contingency table, we also wanted to examine whether the school offered online education is associated with the country’s economic developmental level. We used a chi-square test to do so. Our null hypothesis is that the variables are dependent. According to the test results, the degree of freedom is 3 and the p-value is 1.355e-05, which is smaller than 0.05. Therefore, the result is statistically significant and we reject the null hypothesis. We can conclude that the observed outcomes are not likely due to chance and the variables are associated with each other. 
 

We wanted to know if the differences in the means of different income levels are significant. As a result, we decided to use ANOVA. ANOVA is an analytical method that can help us determine whether the difference between group means is larger after accounting for differences in the variance within groups that may lead to highly variable group means from sample to sample. We get a p-value of 0.00194, which is smaller than 0.05. Thus, we can reject the null hypothesis that all group means are equal. We can conclude that not all group means are equal.