2 A Facebook survey was conducted to compare the mobile app

2. A Facebook survey was conducted to compare the mobile app to the web app, to determine if people preferred one app over the other. Each person (case) in the survey rated both the mobile and web Facebook apps, out of 10. Afterwards the Facebook team calculated each person\'s \"score\" by taking the difference of the two ratings given by each person. This is an example of a \"matched pairs\" experiment, where each case is matched with themselves. Suppose that the \"scores\" from a sample of 14 people follow a Normal distribution with standard deviation =4 and mean x=3.

a) What is the probability of seeing results at least as extreme as the Facebook dataset under the assumption that people have no preference between the web/mobile Facebook apps?

b) The null hypothesis in the Facebook experiment is:

     a. People prefer the Facebook mobile app over the Facebook web app.
     b. People prefer the Facebook web app over the Facebook mobile app.
     c. People don\'t have a preference between the Facebook web/mobile apps.
     d. People tend to prefer one type of app over the other.

c) The alternative hypothesis in the Facebook experiment is:

     a. People prefer the Facebook mobile app over the Facebook web app.
     b. People prefer the Facebook web app over the Facebook mobile app.
     c. People don\'t have a preference between the Facebook web/mobile apps.
     d. People tend to prefer one type of app over the other.

Solution