The sum of one-half a number and 7 is twice the number minus 5. What is that, number?
A. 12
B. 8
C. 1.3333
D. 7

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