The average annual wind speed, X, at Bradfield in West Yorkshire has the following probability density function:
f(x)=
\begin{cases}
2txe^{-tx^2} & x > 0, \\
0 & \text{otherwise.}
\end{cases}
For three randomly selected years, we observe the following average wind speeds:
\begin{multline}
x_1 = 5.5 \\
x_2 = 3.5 \\
x_3 = 5.5
\end{multline}