Select all the solutions to this equation. x2 = 121 x = 11 x = 21 x = 61 x = –11 x = –21

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable