Example automated exercise for statistics introduction course

pnorm1.Rnw

<<echo=FALSE, results=hide>>=
## DATA GENERATION
mean.val<-round(rnorm(1,mean=100,sd=100),digits=0)
sd.val<-round(rnorm(1,mean=100,sd=10),digits=0)

upper<-round(rnorm(1,mean=100,sd=100)+50,digits=0)
lower<-round(rnorm(1,mean=100,sd=100)-100,digits=0)

sol<-pnorm(upper,mean=abs(mean.val),sd=abs(sd.val))-pnorm(lower,mean=abs(mean.val),sd=abs(sd.val))
sol<-round(sol,digits=3)
@

\begin{question}
Given a normal distribution with mean \Sexpr{abs(mean.val)} and standard deviation \Sexpr{abs(sd.val)}, use the \texttt{pnorm} function to calculate the probability of obtaining values between $\Sexpr{format(lower)}$ and $\Sexpr{format(upper)}$ from this distribution.
\end{question}

\begin{solution}

\begin{verbatim}
sol<-pnorm(upper,
           mean=abs(mean.val),
           sd=abs(sd.val))-
  pnorm(lower,mean=abs(mean.val),
        sd=abs(sd.val))
(sol<-round(sol,digits=3))
\end{verbatim}

\Sexpr{sol}
\end{solution}

%% META-INFORMATION
%% \extype{string}
%% \exsolution{\Sexpr{sol}}
%% \exname{pnorm1}
%% \extol{0.0}