Probabilistic and Probabilistic and Statistical TechniquesStatistical Techniques

1

Eng. Ismail Zakaria El Daour

2010

2

Probabilistic and Statistical Techniques

Suppose that past history shows that 60% of college students prefer Brand C cola. A sample of 5 students is to be selected. •The probability that exactly 1 prefers brand C is•The probability that at least 1 prefers brand C is•The probability that exactly 3 prefer brand C is •The probability that at most 2 prefer brand C is •The probability that more than 3 prefer brand C is•The probability that less than 2 prefer brand C is

3

Probabilistic and Statistical Techniques

•The probability that exactly 1 prefers brand C is 0.0768•The probability that at least 1 prefers brand C is 0.9898•The probability that exactly 3 prefer brand C is 0.3456•The probability that at most 2 prefer brand C is 0.3174•The probability that more than 3 prefer brand C is 0.3370•The probability that less than 2 prefer brand C is 0.0870

4

The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with mean = 110 grams and S.D = 25 grams. • What is the probability that a randomly selected vitamin will contain at least 100 grams of pyridoxine?

• What is the probability that a randomly selected vitamin will contain between 100 and 120 grams of pyridoxine?

Probabilistic and Statistical Techniques

• What is the probability that a randomly selected vitamin will contain at least 100 grams of pyridoxine?

0.6554• What is the probability that a randomly selected

vitamin will contain between 100 and 120 grams of pyridoxine?

0.3108

5

Probabilistic and Statistical Techniques

6

Suppose Z has a standard normal distribution with a mean of 0 and standard deviation of 1.

The probability that Z is less than -2.20 is0.0139

Probabilistic and Statistical Techniques

7