ALL 3.The mean of a data set of 20 elements is 10, if we add the data 10, what is the mean of the new data set? 4. A data set has a sample standard deviation s=2, and =1.8. Find ( )2 5. Given P(A c)= 0.7, P(B)=0.5, P(B|A)= 0.3, find P(A and B), P(A or B) and P(A|B). 6. One professor grades homework by randomly choosing 3 out of 7 homework problems to grade. If a student completed the selected problems, he or she will get a perfect score. Elise did 5 problems. What is the probability that she will get a perfect score? 7. In a meeting room there are 5 chairs and 3 people. How many different ways the people can be seated