Dr. Sanders teaches ECON301 at the Maple Leaf University. By the end of Fall 2019 term, Dr. Sanders wants to conduct focus group on a sample of 8 students chosen from her class with regards to students' overall satisfaction of the course learning.

1) Name and briefly describe 3 different sampling methods that can be used by Dr. Sanders to choose a random sample of 8 students from his class. [ 3pt ]

2) After the sample selection, each of the 8 chosen students gave a satisfaction score (out of 5 pts) which is recorded below: 4.5 4.9 4.3 3.9 4.7 3.5 4.6 4.1

Help Dr. Sanders construct a 90% confidence interval for the population mean (i.e. average student satisfaction score in Dr. Sander's ECON 301 class). [ 2pt ]

3) Suppose there are totally 50 students in Dr. Sander's ECON301 class. With this additional information, find the 95% confidence interval for the population mean (i.e. average student satisfaction score in Dr. Sander's ECON 301 class). [ 3pt ]