Question 9 2 pts A simple random sample of size n =[20 is obtained from a population with u = 42 and o = 7. What must be true about the population distribution in order to use the normal model to compute probabilities involving the sample mean? Text View an Example + O The population must be normally distributed. The sampling distribution must be assumed to be normal. Since the sample size is large enough, the distribution of the population does not need to be normal. The population must be normally distributed and the sample size must be large