2. Find a poll that has been conducted at two different time periods or by two different sources. For instance, many polling organizations ask opinions about certain issues on an annual or other regular basis.

a. Create a 2  2 table where “time period” is one categorical variable and “response to poll” is the other, categorized into just two choices, such as “favor”

and “do not favor” for an opinion question.

b. State the null and alternative hypotheses for comparing responses across the two time periods. Be sure you differentiate between samples and populations.

c. Carry out a chi-square test to see if opinions have changed over the two time periods.

d. Write a few sentences giving your conclusion in words that someone with no training in statistics could understand.