A biology professor responds to some student questions by e-mail. The probability model below describes the number of e-mails that the professor may receive from students during a day. e-mails received Probability 0 5 1 3 4 0.05 0.10 0.20 0.25 0.30 0.10 a. How many e-mails should the professor expect to receive each day? b. What is the standard deviation? c. If it takes the professor an average of ten minutes to respond to each e-mail, how much time should the professor expect to spend responding to student e-mails each day?
