SOLUTION: The probability of success on a single trial of a binomial experiment is known to be 0.45. The random variable x, number of successes, has a mean of 81. (a) Find the number of tr

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Question 914936: The probability of success on a single trial of a binomial experiment is known to be 0.45. The random variable x, number of successes, has a mean of 81.
(a) Find the number of trials involved in this experiment. (Give your answer correct to the nearest whole number.)

(b) Find the standard deviation of x. (Give your answer correct to two decimal places.)

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
p = .45
np = 81
n(.45) = 81
n = 81/.45 = 180 trials
sd = sqrt%28.45%28.55%29180%29 = 7 (nearest whole number)