Hernando owns a bowling alley, and recently noticed that he was drawing in an older crowd. Before considering advertising to teenagers, he wanted to gather some data to confirm his suspicion. So Hernando randomly selects $31$ of his customers, records their ages, and constructs a confidence interval to estimate the average age of people who come to his bowling alley. His sample gives a mean of $\bar x =44$ years and a standard deviation of $s_x=12.15$ years. The resulting confidence interval is $\left(38,50\right)$. **Which of the following is closest to the confidence level that Hernando used?** [[☃ radio 1]]