The mean is the sum of all values divided by the number of values in the data set. For numerical variables, the mean represents the expected value of the distribution.

In this case, the values in the data set are Democrat, Republicans, Independent or Other response (to which numbers were assigned).

However, the variable of interest is then not numerical but categorical (as the variable has certain categories in which the response is divided) and the mean can then not be interpreted as it is not meaningful when the variable is not numerical.

In this case, the values in the data set are Democrat, Republicans, Independent or Other response (to which numbers were assigned).

However, the variable of interest is then not numerical but categorical (as the variable has certain categories in which the response is divided) and the mean can then not be interpreted as it is not meaningful when the variable is not numerical.