The CBS TV show 60 min has been successful for many years. It is shown that among the TV sets in use 20% were tuned to 60 min. Assume that an advertiser want to verify that 20% share value by conducting its own survey and a pilot survey begins with 15 households having TV sets in use at the same time of a 60 min broadcast
A) find the probability that five of the households are tuned to 60 min

Question

The CBS TV show 60 min has been successful for many years. It is shown that among the TV sets in use 20% were tuned to 60 min. Assume that an advertiser want to verify that 20% share value by conducting its own survey and a pilot survey begins with 15 households having TV sets in use at the same time of a 60 min broadcast
A) find the probability that five of the households are tuned to 60 min

anonymous · Answer

There's a $20\%$ probability of "success", where "success" refers to being tuned to the show. So, we'll assume a binomial distribution here.

Then
$$P(X=5)=\binom{15}5(0.2)^{15-5}(0.8)^5=\cdots$$