To find the variance of a data set, we follow these steps: First, calculate the mean (average) of the data points. Then, subtract the mean from each data point to find the deviation of each point from the mean. Next, square each of these deviations to eliminate negative values and emphasize larger deviations. After that, calculate the mean of these squared deviations, which gives us the variance. Finally, if required, round the result to the nearest tenth. In this case, the variance of the data set is approximately 6.0.