A binomial experiment consists of 9 independent trials. The probability of success in each is 0.4.

Question

a) Using the tables findP(X(less than or equal to symbol) 3).
b) Find the mean and standard deviation of the random variable associated with this experiment.

a) I used the table in the back of my textbook for this.
I think its : p(x+0) + p (x+1) + p(x+2)+ p(x+3)
= 0.010 + 0.060 + 0.161+ 0.251 = 0.482

b) Mean = np = 9 * 0.4 = 3.6
SD = Sq root of 9*0.4*0.4= 1.47

**Also I can only use the np formula and square root of npq for binomials right?