Assume that a procedure yields a binomial distribution with n trials and the probability of success for one trial is p. Use the given values of n and p to find the mean μ and standard deviation σ. Also, use the range rule of thumb to find the minimum usual value μ - 2σ and

the maximum usual value μ + 2σ.
n = 1445, p = 2/5
I could use some help in figuring this out!