7. (4 marks) Suppose that 70% of the voting population in a large Canadian city is…
7. (4 marks) Suppose that 70% of the voting population in a
large Canadian city is in favour of permitting construction of a
Level IV virus laboratory in the inner city. The city is
contemplating having a referendum on the issue. A random sample of
four eligible voters is interviewed. Among those persons to be
interviewed:

What is the probability that at least three people favour
allowing construction? 
What is the expected number of persons in favour of allowing
construction? 
What is the variance of the number of persons in favour of
allowing construction?