(9). A computer store finds when the customer purchasing one model of computer, 30% upgrade the ram from 16GB to 32GB, the remaining 70% customer do not upgrade. Define events: Y = {upgrade ram}, N = {not upgrade ram}. 1(7). For three randomly selected customers who purchase the computer, record their upgrade options and list all possible outcomes in sample space. Let random variable X be the number of customers who upgrade the ram, find the distribution (pmf) of X. 2(2). Calculate the expected value for X defined in part 1.