1. Time spent using email per session is normally distributed with of 8 minutes, with a population standard deviation () of 2.5 minutes. A sample of 25 sessions is drawn.

1. What is the probability that a sample mean will be between 7.8 and 8.4 minutes?

1. What is the probability that a sample mean will be between 7.6 and 8.2 minutes?

1. Why do I need to state that the distribution of measures of time spent using email per session is normal in order to do parts a and b of this problem? Please answer in a single sentence.

d. Is the normal distribution a "continuous" or a "discrete" distribution? In a single sentence, explain why?