For a study on teen social habits, Nolan is interested in seeing if the average number of texts students sent this past Friday differs between two schools. He randomly samples $40$ students from each of these two schools and finds that the students at one school sent an average of $45$ texts with a standard deviation of $6$ texts, while students from the other school sent $36$ texts on average with a standard deviation of $5$ texts. **Determine the confidence level used if a confidence interval estimate for the difference in the average number of texts sent based on the results above is $(6.06, 11.94)$.** [[☃ radio 1]]