A study has been done to determine whether two different doses of a drug lead to an improvement in symptoms for patients with a particular disease. 500 patients were administered drug dose 1 while 400 patients were administered drug dose 2. They were then asked if there was an improvement in their symptoms after 48 hours. The results are shown in the following table.

	Drug Dose 1	Drug Dose 2	Total
Symptoms improved	320	120	440
No improvement	180	280	460
Total	500	400	900

One patient is selected at random.

Event A: Patient was administered Dose 1

Event B: Patient show Improvement

6. What is P (A)?	A 0.35	B 0.56	C 0.44	D 0.64
7.What is P (A B)?	A 0.64	b 0.356	C 0.489	D 0.727
8.What is P (B | A)?	A 0.64	B 0.056	C 0.73	D 0.36

The number of PRINTERS sold during a week in a particular store in North Ryde is given bellow along with the probability distribution

X	0	1	2	3	4
(P(X)	0.1	0.2	0.2	0.3	0.2

9. What is the expected value for the number of Printers sold in a week?	A 2.3	B 1.0	C 2.1	D 1.5
10. What is probability that the store sells less than three Printers in a week?	A 0.8	B 0.3	C 0.5	D 0.2