Question 465865
The experiment follows a binomial distribution with
the r.v. X = # of correct answers.
n = 30, p = 1/5, q = 4/5

mean {{{mu = np = 30*(1/5) = 6}}}

variance {{{sigma^2 = npq = 30*(1/5)*(4/5) = 4.8}}}, and 

standard deviation {{{sigma = sqrt(4.8) = 2.19}}}, to 2 decimal places.