Complete Question
 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 confirm 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 sample mean?
Answer:
Sample Mean 

Explanation:
From the question we are told that:
Population Mean 

Standard deviation 

Sample size 

Sample Mean 

Therefore
The numerical value of the sample mean is
Sample Mean 
