Fifteen people were asked to indicate their preference for domestic versus imported cars. The following data showed their preferences.
Individual Domestic vs. Imported
1 +
2 +
3 -
4 +
5 +
6 +
7 -
8 +
9 +
10 +
11 +
12 +
13 +
14 +
15 -
With a= 0.05, test for a significant difference in the preferences for cars. A "+" indicates a preference for imported cars.