Statistic probability , etc.
1. If a set of measurement has a mean of 45 and a standard deviation 5, convert the value of X into standard units where X = 55.
2. A random sample of 250 working adults found that 37% access the Internet at work, 44% access Internet at home, and 21% access it at both work and home. What is the probability that a person in this sample selected at random accesses the Internet at home or at work?
3. Suppose that P(A) = .6, P(B) = .3, and events A and B are mutually exclusive:
(a) Find the probability of A or B
(b) Find the probability of A and B
4. Find: (a) the normal curve area which lies between z = – .33 and z = .57; and,
(b) z if the normal curve area between – z and + z is .7888
5. The number of ounces of soda that a vending machine dispenses per cup is normally distributed with a mean of 12 oz. and a standard deviation of 4 oz. Find the probability that:
(a) more than 16 oz. is dispensed in a cup; and,
(b) between 15 and 18 oz. are dispensed in a cup
