Given below is a table of summarized data from a 2013 study of a nationally representative sample of U.S. adults by the Gallup organization, where participants were asked about their political leaning as well as their opinionon whether there should be a tax on unhealthy food/soda. 

a. Is this an experiment or an observational study? How are you deciding?

b. Identify the observational units.

c. Identify the explanatory and response variables. Also, for each variable, identify whether it is categorical or quantitative.

d. Define the parameters of interest. Assign symbols to these parameters.

e. State the appropriate null and alternative hypotheses in symbols.

f. State the appropriate null and alternative hypotheses in words

g. Explain why it would be okay to use the theory-based method to find a p-value for this study.

h. Use an appropriate applet (for example, the Multiple Proportions applet) to find and report the following from the data: (i) the name of the statistic and its numeric value and (ii) the theory based p-value.

i. Interpret the p-value in the context of the study.

j. State a complete conclusion about this study, including significance, causation, and generalization. Be sure to explain how you are arriving at your conclusion.

k. If relevant, use an applet to find and report a set of confidence intervals appropriate for the context. Also, interpret the confidence intervals in the context of the study. If not relevant, explain why it is not particularly useful to look at confidence intervals for the parameter(s) of interest in the context of this study.

Political leaning Republican Democrat Independent Total Favor tax on unhealthy food/ soda? 127 273 246 646 Yes No 403 500 1,237 334 Total 607 530 746 1,883