The number of large packages delivered by a courier service follows a Poisson distribution with a rate of 5 per day.
Let X be the number of large packages delivered on a given day. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part.

Find σX.

σX = 2.24

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

In which

x is the number of sucesses

e = 2.71828 is the Euler number

is the mean in the given time interval. The variance is the same as the mean.

Find σX.

This is the standard deviation, which is the square root of the variance.

Mean = variance = 5

sqrt(5) = 2.24

So

σX = 2.24