I am struggling with the below question concerning normal distribution. I found a. easily but I am struggling with b. I know I need to find the mean value and the standard deviation but am unsure of how to find those values with the given information. So my question is how to calculate the mean and variance?
My class has n = 100 students, and each has a p = 0.75 chance of showing attending on a given day. (A student?s attendance is independent of what others are doing.)
a. What is the probability that no more than 80 students show up for class today?
b. ** Approximate the answer using the normal distribution. How do the exact and approximate results compare?