) In New South Wales, each adult on the electoral roll has a 10% of being called up for jury duty in any year. A company has 25 employees on the electoral roll. i) What is the probability that more than two employees are called up for jury duty in any year

Respuesta :

Answer:

The probability is [tex]0.4629[/tex]

Step-by-step explanation:

We know that in New South Wales, each adult on the electoral roll has a 10 % of being called up for jury duty in any year.

We can write this probability as :

[tex]p=0.1[/tex]

We also know that a company has 25 employees on the electoral roll.

We can write this as :

[tex]n=25[/tex]

Now we can assume that this is a Bernoulli process in which the election of a random adult is independent and also the probability of being called remains the same [tex](p=0.1)[/tex]

We also define the Binomial random variable in the Bernoulli process that counts the number of successes given that we set a number of individual experiments.

In this exercise, we will call a ''success'' when an adult is being called up for jury duty. We also set the number of experiments to [tex]n=25[/tex] (being this number the total employees of the company).

We define the random variable as :

[tex]X :[/tex] '' Number of employees being called up for jury duty in any year from the total of 25 employees ''

⇒ [tex]X[/tex] ~ Bi ( n , p ) ⇒ [tex]X[/tex] ~ Bi ( 25 , 0.1 )

This means that [tex]X[/tex] can be modeled as a Binomial random variable with parameters ''n'' and ''p''.

We can calculate probabilities using the following equation :

[tex]P(X=x)=(nCx)p^{x}(1-p)^{n-x}[/tex]

Where [tex]nCx[/tex] is the combinatorial number define as :

[tex]nCx=\frac{n!}{x!(n-x)!}[/tex]

We want to calculate [tex]P(X>2)[/tex] ⇒

[tex]P(X>2)=1-P(X\leq 2)[/tex]   ⇒

[tex]P(X>2)=1-[P(X=0)+P(X=1)+P(X=2)][/tex]

[tex]P(X>2)=0.4629[/tex]

 We found out that the probability is [tex]0.4629[/tex]

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