Online applications. Researchers for an online marketing company suggest that new customers who have to become a member before they can check out on the website are very intolerant of long applications. One way to rate an application is by the total number of keystrokes required to fill it out.

a) One common frustration is having to enter an e-mail address twice. If the mean length of e-mail addresses is 13.3 characters, with a standard deviation of 2.8 characters, what is the mean and standard deviation of total characters typed if entered twice?

b) The company found the mean and standard deviation of the length of customers’ names (including spaces)

were 13.4 and 2.4 characters, respectively, and for addresses, 30.8 and 6.3 characters. What is the mean and standard deviation of the combined lengths of entering the e-mail addresses twice and then the name and the address?