25 Questions mixed types from a STAT class

A sample of 20 observations has a standard deviation of 4. The sum of the squared deviations from the sample mean is:What type of probability uses sample spaces to determine the numerical probability that an event will occur?If A and B are any two events with P(A) = .8 and P(B|A) = .4, then the joint probability of A and B isFind the variance of the following probability distribution.XP(X)10.2020.3530.1040.2550.10Which term is NOT synonymous with the expected value of a discrete probability distribution?If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices.The continuous distribution characterized by a symmetric, bell-shaped curve is the:The standard deviation of a probability distribution must be:The mean of a probability distribution can be:The standard deviation of  is usually called theThe theorem that states that the sampling distribution of the sample mean is approximately normal when the sample size n is reasonably large is known as the:The standard normal distribution has a mean of ___ and standard deviation of ___, respectively.rest on attach