Posted by ghb on .
the probability that an imdividual is lefthanded is 0.30 in a class of 25 students, what is the the mean and standard deviation of the number of lefthanders in the class

math 
MathGuru,
Mean = np = 25 * .3 = ?
Standard deviation = √npq = √(25)(.3)(.7) = ?
Note: q = 1  p
I'll let you finish the calculations.