Surgery is in 4 out if every 10 hospital emergency room visits. If a large urban hospital had 840 emergency visits in the past month how many of these visits would you expect to required surgery

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:

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:

Compute the expected number of visits that would require a surgery as follows:

Thus, expected number of visits to the emergency room that would require a surgery is 336.

all it means is function 3

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240