A Report in the Des Moines Register Presented the Average

Essay

A report in the Des Moines Register presented the average number of years of
teaching experience for the teachers in elementary schools in Des Moines, Iowa.
These data appear in the table below. $\begin{array}{|l|l|l|c|l|l|l|c|}\hline \text { School } & \begin{array}{c}\text { Average } \\\text { Years } \\\text { Exper. }\end{array} & \text { School } & \begin{array}{c}\text { Average } \\\text { Years } \\\text { Exper. }\end{array} & \text { School } & \begin{array}{c}\text { Average } \\\text { Years } \\\text { Exper. }\end{array} & \text { School } & \begin{array}{c}\text { Average } \\\text { Years } \\\text { Exper. }\end{array} \\\hline \text { Adams } & 13.8 & \text { Hanawalt } & 12.7 & \text { McKee } & 17.5 & \text { Phillips } & 10.5 \\\begin{array}{l}\text { Capitol } \\\text { View }\end{array} & 9.7 & \text { Hillis } & 17 & \text { McKinley } & 5.6 & \text { Pleasant } & 12.8 \\& & & & \text { Hill } &\\\text { Cattell } & 8.5 & \text { Howe } & 14.9 & \text { Mitchell } & 6.2 & \begin{array}{l}\text { River } \\\text { Woods }\end{array} & 5.9 \\\text { Douglas } & 13.8 & \text { Hubbell } & 15.1 & \text { Monroe } & 16.2 & \text { Stowe } & 16.5 \\\text { Downtown } & 7.0 & \text { Jackson } & 16.8 & \text { Moore } & 16.6 & \text { Studebaker } & 18.4 \\\text { Edmunds } & 8.4 & \text { Jefferson } & 19.2 & \text { Morris } & 9.9 & \text { Wallace } & 4.8 \\\text { Findley } & 14.9 & \text { King } & 7.0 & \text { Moulton } & 8.6 & \text { Willard } & 9.7 \\\text { Garton } & 9.3 & \text { Longfellow } & 9.8 & \text { Oak Park } & 11.4 & \text { Windson } & 17.7\\\text { Granger } & 17.2 & \text { Lovejoy } & 9.9 & \text { Park } & 11.4 & \text { Woodlawn } & 17\\\text { Greenwood } & 14 & \text { Madison } & 20.8 & \text { Perkins } & 11.2 & \text { Wright } & 12.9 \\\hline\end{array}$ (a) Sketch a histogram for these data, using the following class intervals:
$$\begin{array} { l } 0 \text { to } < 4 \\4 \text { to } < 8 \text {, etc. }\end{array}$$ (b) Describe the distribution of the average number of years of teaching experience,
and note any unusual features.