Suppose we wish to know if there is a difference in choice of model based on comfort between population groups classified as under-weight, normal weight, or over-weight. To make this determination 600 people were classified in one of the three weight classes and then asked to select the most comfortable seat. The results are summarized in the following table.
Seat Preference
Weight Class: Model A Model B Model C
Under-Weight 100 40 50
Normal-Weight 90 70 60
Over-Weight 40 60 90
A) Write an appropriate null and alternative hypothesis.
B) Compute the expected frequency for the first cell in row one.
C) Test the null hypothesis at the 0.05 significance level. Make a decision to reject or fail to reject the null based on the p-value.
D) Draw a conclusion about the relationship between weight and type of seat based on comfort.