In an Analysis of Hunting by African Lions, Biologists Filmed

In an analysis of hunting by African lions, biologists filmed prey captures from the
safety of their vehicles. Prey captures were then divided into a sequence of events.
One of the events is the stalk, defined as the reduction of predator-prey distance for
prey that has been specifically targeted. The investigators identified two types of
stalk: (a) "crouching," -- the lion is concealed and either the lion advances toward the
prey or the prey advances (unaware) toward the lion, and (b) "running," -- the lion is
less concealed and advances toward the prey in a rapid manner.
Data on lions' stalks of wildebeests and zebras from a simple random sample of 159
kills are summarized in the table below. $$\begin{array} { | l | l | } \hline { \text { Characteristic } } & { \begin{array} { c } \text { Numeric } \\\text { value }\end{array} } \\\hline \text { Mean stalking time } & 31.6 \mathrm {~min} \\\text { Standard deviation of stalk time } & 16.4 \mathrm {~min} \\\text { Proportion of stalks of the crouching type } & 0.92 \\\hline\end{array}$$ Researchers believe that the proportion of stalks that are the crouching type is about 0.87. Do the data above provide evidence that the researchers' belief is incorrect and
that the proportion of crouching stalks of wildebeests and zebras is different from 0.87?