COVID-19 pandemic

Sample Solution

The variable of interest in the scenario is political party affiliation. It has three levels:

• Republican
• Democrat
• Other

2. Calculate the expected frequencies for each of the levels of your variable. Clearly label each group and show all work involving your calculations.

To calculate the expected frequencies, we use the following formula:

Expected frequency = (Row total * Column total) / Total number of observations

Row total: The total number of observations in each row. Column total: The total number of observations in each column. Total number of observations: The total number of observations in the table.

Pre-pandemic voting based on political party affiliation:

| Political party affiliation | Observed frequency | Expected frequency |
|---|---|---|
| Republican | 25 | 26.25 |
| Democrat | 30 | 33 |
| Other | 20 | 15.75 |
| Total | 75 | 75 |

Calculations:

Expected frequency for Republicans: (75 * 35%) / 75 = 26.25
Expected frequency for Democrats: (75 * 44%) / 75 = 33
Expected frequency for Others: (75 * 21%) / 75 = 15.75

Therefore, the expected frequencies for each of the levels of the variable are:

• Republican: 26.25
• Democrat: 33
• Other: 15.75

Conclusion

Once we have calculated the expected frequencies, we can use them to conduct a chi-square test of independence to determine if there is a significant difference between the pre-pandemic and post-pandemic voting patterns.