Chapter 12.1, Problem 7E

The authors of the paper “Is It Really About Me? Message Content in Social Awareness Streams” (Computer Supported Cooperative Work 2010) studied a random sample of 350 Twitter users. For each Twitter user in the sample, the tweets sent during a particular time period were analyzed and the Twitter user was classified into one of the following categories based on the type of messages they usually sent:

The accompanying table gives the observed counts for the five categories (approximate values read from a graph in the paper).

Carry out a hypothesis test to determine if there is convincing evidence that the proportions of Twitter users falling into each of the five categories are not all the same. Use a significance level of 0.05. (Hint: See Example 12.2.)