This question is based on the following circle graph. The graph represents the results of a survey in which 400 people were asked to identify the TV channel on which they preferred to watch the evening news.
![458_The Results of a Survey Graph.jpg](https://secure.tutorsglobe.com/CMSImages/458_The%20Results%20of%20a%20Survey%20Graph.jpg)
How many more people preferred WWCN than WANR?