According to diffusion of innovation, in order for an innovation to ultimately be adopted it has to be

At a small store, a customer enters the front door on average every 8 minutes. a prior study indicated that the time between customers entering the front door during weekdays follows an exponential distribution. what is the probability that the time between customers entering the store on a weekday will be less than or equal to 7? select one: a. 62 b. 43 c. 1/8 d. 7/8 e. 58