Find the Mean for the Given Sample Data $\begin{array} { l l l } 55 & 64 & 68 \end{array}$

Multiple Choice

Find the mean for the given sample data. Unless otherwise specified, round your answer to one more decimal place thanthat used for the observations.
-Last year, nine employees of an electronics company retired. Their ages at retirement are listed below. Find the mean retirement age.
$\begin{array} { l l l } 55 & 64 & 68 \end{array}$
$\begin{array} { l l l } 56 & 64 & 58 \end{array}$
$\begin{array} { l l l } 64 & 57 & 51 \end{array}$

A) $59 \mathrm { yr }$
B) $59.7 \mathrm { yr }$
C) $58.4 \mathrm { yr }$
D) $58 \mathrm { yr }$