For exercise 14 given a binomial situation with n 5 p 08
Solution
6.
Note that P(more than x) = 1 - P(at most x).          
           
 Using a cumulative binomial distribution table or technology, matching          
           
 n = number of trials =    8      
 p = the probability of a success =    0.3      
 x = our critical value of successes =    7      
           
 Then the cumulative probability of P(at most x) from a table/technology is          
           
 P(at most   7   ) =    0.99993439
           
 Thus, the probability of at least   8   successes is  
           
 P(more than   7   ) =    0.00006561 [answer]
9.
Note that the probability of x successes out of n trials is          
           
 P(n, x) = nCx p^x (1 - p)^(n - x)          
           
 where          
           
 n = number of trials =    9      
 p = the probability of a success =    0.5      
 x = the number of successes =    4      
           
 Thus, the probability is          
           
 P (    4   ) =    0.24609375 [answer]
13.
Note that the probability of x successes out of n trials is          
           
 P(n, x) = nCx p^x (1 - p)^(n - x)          
           
 where          
           
 n = number of trials =    12      
 p = the probability of a success =    0.1      
 x = the number of successes =    0      
           
 Thus, the probability is          
           
 P (    0   ) =    0.282429536 [answer]
15.
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 =    12      
 p = the probability of a success =    0.1      
 x = our critical value of successes =    3      
           
 Then the cumulative probability of P(at most x - 1) from a table/technology is          
           
 P(at most   2   ) =    0.889130022
           
 Thus, the probability of at least   3   successes is  
           
 P(at least   3   ) =    0.110869978 [answer]


