The following values are a random sample of temperatures (in degrees Fahrenheit) at a town in Canada. Assume data values are normally distributed.
\begin{tabular}{|r|}
\hline 26.7 \\
\hline 23.8 \\
\hline 28.8 \\
\hline 20.9 \\
\hline 29.1 \\
\hline 21 \\
\hline 12.8 \\
\hline 10.2 \\
\hline 23.8 \\
\hline 28 \\
\hline 21.3 \\
\hline 37.4 \\
\hline
\end{tabular}
Find the \( 90 \% \) confidence interval for the mean temperature. Enter your answer as an open-interval (i.e., parentheses (\#,\#)) accurate to two decimal places.
\[
90 \% \text { C.I. }=
\]
\( \square \)