A class has 80 students. Test 2 had a class average of 78 and a variance of 49. Answer the following 7 questions. (Assume Normal distribution). Assume a 90-80-70-60 scale; Do not round off answers.
1. What is the probability of getting an A?
2. How many will get an A?
3. What is the probability of getting a B?
4. What is the probability of getting a C?
5. How many people will fail the class?
6. If the bottom 5% will get an F, what will be the cut-off score?
7. If the top 15% get an A, what is the cutoff score for an A?