The following represents the probability distribution of the number of classes a student takes in a spring semester.

x P(x) 1 0.115 2 3 0.422 4 0.312 5 0.034 6 0.015

Find the missing probability.

Respuesta :

Answer:

X        1       2       3         4          5          6

P(X) 0.115   a     0.422   0.312   0.034   0.015

If we want a probability distribution we need to satisfy two important conditions:

1) [tex]P(X_i) \geq 0, \forall i=1,2,3,4,5,6[/tex]

2) [tex]\sum_{i=1}^n P(X_i) =1[/tex]

And using the second condition we have this:

[tex] 0.115+a+0.422+0.312 +0.034 +0.015=1[/tex]

With a the probability associated with the value of X=2 and solving for a we got:

[tex] a = 1-0.115-0.422-0.312-0.034-0.015= 0.102[/tex]

So then for this case [tex] P(X=2) = 0.102[/tex]

Step-by-step explanation:

Let X the random variable that represent the number of classes that a student takes

For this case we have the following probability distribution given:

X        1       2       3         4          5          6

P(X) 0.115   a     0.422   0.312   0.034   0.015

If we want a probability distribution we need to satisfy two important conditions:

1) [tex]P(X_i) \geq 0, \forall i=1,2,3,4,5,6[/tex]

2) [tex]\sum_{i=1}^n P(X_i) =1[/tex]

And using the second condition we have this:

[tex] 0.115+a+0.422+0.312 +0.034 +0.015=1[/tex]

With a the probability associated with the value of X=2 and solving for a we got:

[tex] a = 1-0.115-0.422-0.312-0.034-0.015= 0.102[/tex]

So then for this case [tex] P(X=2) = 0.102[/tex]