9. The number of suits sold per day at Suit World is shown in the probability distribution below. (10 points) X 2 4 5 9 P(X) 0.3 0.3 0.2 0.2 Find the mean. variance. and standard deviation of the distribution. X P(X) Mean = Variance = Standard Deviation = 10. A medical treatment is successful 76% of the time. A hospital wishes to treat a group of patients. How many patients should they take so that the probability that all are cured is 0.05? (5 points) 11. A manufacturer makes 10 000 ball point pens per dayr and estimates that 150 will be defective. She decides that if a random sample of 20 pens contains more than one defective pen, then she will institute quality-control measures. (5 points) a) Find the probability that there are more than one defective. 12. A drug company claims their new u vaccine cures 89% of patients. What is the probability that in a family of five people who take the vaccine? (a) At most four get the u? (5 points) (b) At least one gets the u? (5 points) 13. Ime- Bi (10, 0.4), nd (5 points) (a) PCX: 9) (Extra Credit 5 points) (b) P (X: 1)