Consider the following binomial experiment A company owns 4

Consider the following binomial experiment: A company owns 4 copiers. The probability that on a given day any one copier will break down is 0.54. What is the probability that at least 2 copiers will break down on a given day?

Solution

Note that P(at least x) = 1 - P(at most x - 1).          
          
Using a cumulative binomial distribution table or technology, matching          
          
n = number of trials =    4      
p = the probability of a success =    0.54      
x = our critical value of successes =    2      
          
Then the cumulative probability of P(at most x - 1) from a table/technology is          
          
P(at most   1   ) =    0.25502032
          
Thus, the probability of at least   2   successes is  
          
P(at least   2   ) =    0.74497968   [ANSWER]