The first two immigrant species are appealing to eco-tourists, and each additional individual brings in $1000. The third species is repellent to eco-tourists and reduces revenue by $500.
a. Find the expected revenue from each species separately and for all species together.
b. Find the variance in revenue due to each species separately.
c. Find the variance in the total revenue if the species immigrate independently.
d. Interpret these results.
Suppose annual immigration into a park by three species follows the probabilities in the table.

Number of Immigrants Species 1 0.3 0.6 0.1 Species 2 0.6 0.2 0.2 Species 3 0.1 0.3 0.6