SOLUTION: 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 u and stan

Click here to see ALL problems on Probability-and-statistics

Question 1058230: 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 u and standard deviation o. Also, use the range rule of thumb to find the minimum usual value u - 2o and the maximum usual value u +2o
n = 1552, p = 1/4
u = 388
o= 17.1 (Round to one decimal place as needed)
u - 2o = 353.8 (Round to one decimal place as needed)
u + 2o = 422.2 (Round to one decimal place as needed)

Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website!
The mean is 1552*1/4=388
The variance is 388*(3/4), or np(1-p)
That is 291
The sd is the sqrt (291)=17.06
Mean + 2sd is 422.1 (I round at the end)
Mean - 2sd is 353.9
What you did was fine.