When 14 different second-year medical students at Bellevue Hospital measured the blood pressure of the same person, they obtained the results listed below. Assuming that the population standard deviation is known to be $10 \mathrm{mmHg}$, construct a $95 \%$ confidence interval estimate of the population mean. Ideally, what should the confidence interval be in this situation?
$$\begin{array}{rrrrrrrrrrrrrr}
138 & 130 & 135 & 140 & 120 & 125 & 120 & 130 & 130 & 144 & 143 & 140 & 130 & 150
\end{array}$$