excel A car insurance company has determined that 8% of all drivers were involved in a car accident last year. If 15 drivers are randomly selected, what is the probability of getting 3 or more who were involved in a car accident last year

Respuesta :

Answer:

[tex] P(X \geq 3)= 1- P(X<3)= 1-P(X \leq 2)= 1- [P(X=0) +P(X=1) +P(X=2)][/tex]

And we can find the individual probabilites using the probability mass function and we got:

[tex] P(X=0) = (15C0) (0.08)^{0} (1-0.08)^{15-0}=0.286 [/tex]

[tex] P(X=1) = (15C1) (0.08)^{1} (1-0.08)^{15-1}=0.373 [/tex]

[tex] P(X=2) = (15C2) (0.08)^{2} (1-0.08)^{15-2}=0.227 [/tex]

And replacing we got:

[tex] P(X\geq 3) = 1-[0.286+0.373+0.227 ]= 0.114[/tex]

Step-by-step explanation:

For this case we can assume that the variable of interest is "drivers were involved in a car accident last year" and for this case we can model this variable with this distribution:

[tex] X \sim Bin (n =15, p =0.08)[/tex]

And for this case we want to find this probability;

[tex] P(X \geq 3)[/tex]

and we can use the complement rule and we got:

[tex] P(X \geq 3)= 1- P(X<3)= 1-P(X \leq 2)= 1- [P(X=0) +P(X=1) +P(X=2)][/tex]

And we can find the individual probabilites using the probability mass function and we got:

[tex] P(X=0) = (15C0) (0.08)^{0} (1-0.08)^{15-0}=0.286 [/tex]

[tex] P(X=1) = (15C1) (0.08)^{1} (1-0.08)^{15-1}=0.373 [/tex]

[tex] P(X=2) = (15C2) (0.08)^{2} (1-0.08)^{15-2}=0.227 [/tex]

And replacing we got:

[tex] P(X\geq 3) = 1-[0.286+0.373+0.227 ]= 0.114[/tex]

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