Respuesta :
Answer:
The expected number of items that will be classified into group 1 is 100.
Step-by-step explanation:
For each observation, there are only two possible outcomes. Either it will be classified into group 1, or it will not. The probability of an observation being classified into group 1 is independent of any other observation, which means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
Probability of exactly x successes on n repeated trials, with p probability.
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
400 observations
This means that [tex]n = 400[/tex]
Four mutually exclusive groups. The probability of a randomly selected item being classified into any of the four groups is equal.
This means that [tex]p = 0.25[/tex]
Then the expected number of items that will be classified into group 1 is
[tex]E(X) = np = 400*0.25 = 100[/tex]
100 is the answer.
