Find mean, variance and standard deviation, 45% out of 180.


New member
May 15, 2006
I am wondering if you can get me started on this question.

If 45% of nursing students are able to pass a drug calculation test, find the mean, variance, and standard deviation of the number of students who pass the test in a sample of 180 nursing students.

I know how to find mean when I have a list of numbers but I am not sure what to do with just one.

I am thinking that with the .45 I will use .55 somehow but again not sure.

Just so you know I am a 45 year old who decided to go back to school and statistics is not being kind to me.


Junior Member
Apr 28, 2006
To get you started, the number of students who pass the test has a binomial distribution with parameters n = 180 and p = .45. The formulas for the mean, variance and standard deviation of this distribution should be in your textbook.

I wish you well with your return to school! :)