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Binomial distribution. Nutan S. Mishra Department of Mathematics and Statistics University of South Alabama. Binomial experiment. An experiment is called binomial experiment if it satisfies following four conditions Consists of n trials All the trials are independent.
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Binomial distribution Nutan S. Mishra Department of Mathematics and Statistics University of South Alabama
Binomial experiment An experiment is called binomial experiment if it satisfies following four conditions • Consists of n trials • All the trials are independent. • There are only two possible outcomes of each trial. • Probability of success in each trial is constant say p. X is number of successes in the experiment
Example Toss four fair coins. X= # heads showed up Then x may take values 0 or 1 or 2 or 3 or at the most 4. p = .5, n =4 . Use binomial table to complete the following table
Example In a company it is known that among the population of employees 35% are smokers and 65% are non smokers. If we select a sample of size 10 employees from this population and count the number of smokers is the sample then X= # smokers in the sample of 10 is a binomial variable with n=10 and p= .35 that is (1-p) = .65. The possible values x takes : 0 to 10 Use table of combinations and a calculator to complete the table on next slide