a certain bakery sells, among other things, a certain type of artisanal bread rolls. Here is some data on the sale of these rolls (which will be referred to as "bread" in the following): The number X of breads purchased per hour is a Lou de Poisson variable with parameter = 1.2.

Determine the variance of the number of loaves bought per half hour and the probability that at least one loaf will sell for a given hour.