Answer:
Expected value = 7 x 0.9 = 6.3
Step-by-step explanation:
Probability of getting a good apple is 18/20 = 0.9
Probability of getting a bad apple is 2/20 = 0.1
This follows a binomial distribution because either you get a good apple or a bad apple.
The expected value of a binomial distribution is given as n*p where n is number of trials and p is the probability of success.
In this case our number of trials is 7 and the probability of success is 0.9, since the trials are for getting good apples.
Hence
n = 7
p = 0.9
Expected value = 7 x 0.9 = 6.3
