To test this idea, I randomly picked 16 friends of mine living in Chandler and asked them how many smart phones and tablets are in their households. The data set is shown below. (The same data are also provided in an Excel file if you choose to use Excel for your calculations.) I would like to perform a Z test to see if the numbers of mobile devices in Chandler households (represented by the sample of 16 households) are significantly higher than the numbers of mobile devices in the national households. The significance level for my Z test was set at a = .05. The hypotheses should be directional because I am predicting a specific direction of difference, and the test should be one-tailed. Subject # # of mobile (Household) devices 6 2 3 3 4 6 5 8 VAUIC 10 11 12 13 w u a 14 15 16 6 a. What is the dependent variable in this study? (1 point)