Question

The number of customers in a line at a supermarket express checkout counter is a random variable with the following probability distribution. x 0 1 2 3 4 5 P(x) 0.09​ 0.26​ 0.29​ 0.20​ 0.09​ 0.07​ Find P(2 or fewer).

Answer 1

`P(X \leq 2)= P(X=0) +P(X=1)+P(X=2)`

And replacing we got:

`P(X \leq 2)= 0.09 +0.26+0.29 = 0.64`

And the probability that X would be 2 or lower is 0.64

Explanation:

For this case we have the following probability distribution:

x 0 1 2 3 4 5

P(x) 0.09 0.26 0.29 0.20 0.09 0.07

And we want to find the following probability:

`P(X \leq 2)`

And we can find the probability like this:

`P(X \leq 2)= P(X=0) +P(X=1)+P(X=2)`

And replacing we got:

`P(X \leq 2)= 0.09 +0.26+0.29 = 0.64`

And the probability that X would be 2 or lower is 0.64

Answer 2

probability (x ≤2) = 0.64

Explanation:

P(2 or fewer) = probability of 2 or fewer

probability of (2 or fewer) = probability (x ≤2)

probability of (2 or fewer) = probability when x is 0 + probability when x is 1 + probability when x is 2

probability of (2 or fewer) = probability (x =0) + probability of (x =1 ) + probability (x= 2)

probability of (x=0) = 0.09​

probability of (x=1) = 0.26​ ​

probability of (x =2) = 0.29

probability of (2 or fewer) = 0.09​ + 0.26​ + 0.29​ = 0.64

probability (2 or fewer) = probability (x ≤2) = 0.64