The article The Need to Be Plugged In (Associated Press, December 22, 2005) described the results of a survey of 1006 adults who were asked about various technologies, including personal computers, cell phones, and DVD players. The accompanying table summarizes the responses to questions about how essential these technologies were. Relative Frequency Personal Cell DVD Response Computer Phone Player Cannot imagine living without .46 .41 .19 Would miss but could do without .28 .25 .35 Could definitely live without .26 .34 .46 Construct a comparative bar chart that shows the distribution of responses for the three different technologies.
Stat notes 2 Categorical data= nominal and ordinal Quantitative data= discrete and continuous Relative frequency table- all #’s in table sum to 1 for percentages Proportion= # in category/ total sample size (risk is the same thing as proportion) How do you know which variable is the response and which is the explanatory Rows= response variable Columns= explanatory variable How do we compare the risks of two different groups By using relative risk - If relative risk is less than, first group has a smaller risk - Odds- ratio of counts of the two levels of one categorical variable haves/have nots Proportion for a sample- p (hat) Proportion for population- P Two-way table- used to show the relationship between two categorical variables Two categorical variables: -
