Hi, I'm afraid my daughter is stumped over a couple of questions and I'm not able to help her as my math is limited to 9/10th grade.
The two questions are as follows:
1).
Given the probability distribution function consider the following:
x = 0, p = 0.25. X = 1, p = 0.5. x = 2, p = 0.25
a). Draw the probability distribution function.
b). Calculate the draw the cumulative probability function.
c). Find the mean of the random variable X.
d). Find the variance of X.
2).
For a binomial probability function with P = 0.5 and n = 12, find the probability that the number of successes is equal to 7, and the probability that the number of successes is fewer than 6.
For the first part of the last question, I think I might have got the answer. I made it 0.19, but I have no idea how to go about the second part.
She's taking a Psychology degree and math isn't her (or my) strongpoint, so any help anybody could throw our way would be really appreciated. If possible, please make your explanations fit 'for dummies'. Thanks. Cheers, Adrian

Your daughter's text book provides the formula for calculating mean and standard deviation - I suggest you and she read it, and if you are still unable to complete this post back and show us your attempt to solve this. The fact that she apparently doesn't know how to sketch the probability distribution suggests she has not read the material.