Exhibit 10-3
a Statistics Teacher Wants to See If There

Exhibit 10-3
A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information. $$\begin{array}{l}& \text { Today } & \text { Five Years Ago } \\\overline { \mathrm { x } } & 82.0 & 88 \\\sigma ^ { 2 } & 112.5 & 54 \\\mathrm { n } & 45.0 & 36\end{array}$$
$$\begin{array}{cc}\text { Today } & \text { Five Years Ago }\\82.0 & 88 \\112.5 & 54 \\45.0 & 36\end{array}$$ $\begin{array}{cc}\text { Today }&\text { Five Years Ago }\\82.0 & 88 \\112.5 & 54 \\45.0 & 36\end{array}$ n
-Refer to Exhibit 10-3. The standard error of is

A) 12.9
B) 9.3
C) 4
D) 2