Standard deviation question.
I am given this data: Blood groups and frequency.
O = 0.45 A = 0.40 B = 0.11 and AB = 0.04.

A random sample of 100 people is selected from this population. Let the random variable X represent the number of people with blood group O in the sample. Calculate the mean and standard deviation of X

Question

Standard deviation question.
I am given this data: Blood groups and frequency.
O = 0.45 A = 0.40 B = 0.11 and AB = 0.04.

A random sample of 100 people is selected from this population. Let the random variable X represent the number of people with blood group O in the sample. Calculate the mean and standard deviation of X

tkhunny · Answer

Can you think of it as a Binomial Distribution with p = 0.45?

anonymous · Answer

Yes

tkhunny · Answer

Well, then:

Mean = np
Variance = npq

anonymous · Answer

what does q stand for in the npq?

tkhunny · Answer

q = 1-p