Answer:
Expected number of visits to the emergency room that would require a surgery is 336.
Step-by-step explanation:
Let X = number of surgery.
The odds of having a surgery in a randomly selected visit to a emergency room is 4 out of 10.
Then the probability of having a surgery in a randomly selected visit to a emergency room is:
[tex]p=\frac{4}{10}=0.40[/tex]
In the past month a large urban hospital had 840 emergency visits.
An emergency room visit may lead to surgery or not is independent of the others.
The random variable X follows a Binomial distribution with parameters n = 840 and p = 0.40.
The expected value of a binomial random variable is:
[tex]E(X)=np[/tex]
Compute the expected number of visits that would require a surgery as follows:
[tex]E(X)=np[/tex]
[tex]=840\times 0.40\\=336[/tex]
Thus, expected number of visits to the emergency room that would require a surgery is 336.