Consider a Study Testing Whether Birds Were Equally Likely to Rest

Consider a study testing whether birds were equally likely to rest on each streetlight. Researchers surveyed 30 randomly chosen streetlights in a city known to have many birds and counted the number of birds resting on each streetlight. Data on the number of birds seen on the lights are shown. (Note: No lights had more than three birds.) Assuming a Poisson process, what is the expected number of streetlights without any birds?
?
$\begin{array}{|cc|}\hline \begin{array}{l}\text { Number } \\\underline {\text { birds }}\end{array} & \begin{array}{l}\text { Number } \\\underline {\text { of lights }}\end{array} \\0 & 3 \\1 & 12 \\2 & 9 \\\geq 3 & 6 \\\hline\end{array}$

A) 3.06
B) 4.06
C) 5.06
D) 6.06