A few years ago, people tended to have relatively large CD collections. For students at a large university in the midwest, the mean number of CDs owned was 78 with a standard deviation of 90. To conrm these numbers, a random sample of 120 students from this university was collected and the size of their CD collections recorded. These particular 120 students had a mean CD collection size of 80 CDs. What is the numerical value of the population mean? 5 80 O 120 IO 78 O .90