60 of the students applying to college are accepted using bi
60% of the students applying to college are accepted, using binominal probability tables, what is the probability that the next 18 applicants: 1. at least 6 will be accepted, 2. exactly 10 will be acceptd, 3. exactly 5 will be rejected, 4. fifteen or more will be accepted, 5. compute standard deviation.
Solution
1.
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 =    18      
 p = the probability of a success =    0.6      
 x = our critical value of successes =    6      
           
 Then the cumulative probability of P(at most x - 1) from a table/technology is          
           
 P(at most   5   ) =    0.005750497
           
 Thus, the probability of at least   6   successes is  
           
 P(at least   6   ) =    0.994249503 [answer]
 **************
 2.
 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 =    18      
 p = the probability of a success =    0.6      
 x = the number of successes =    10      
           
 Thus, the probability is          
           
 P (    10   ) =    0.173400322 [answer]
************
3.
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 =    18      
 p = the probability of a success =    0.6      
 x = the number of successes =    15      
           
 Thus, the probability is          
           
 P (    15   ) =    0.024554941 [answer]
****************
4.
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 =    18      
 p = the probability of a success =    0.6      
 x = our critical value of successes =    15      
           
 Then the cumulative probability of P(at most x - 1) from a table/technology is          
           
 P(at most   14   ) =    0.967218703
           
 Thus, the probability of at least   15   successes is  
           
 P(at least   15   ) =    0.032781297 [answer]
************
5.
standard deviation = sqrt(n p (1 - p) = sqrt(18*0.6*(1-0.6))
=2.078460969 [ANSWER]


