A lakeside food vendor knows from past experience that his sales ratios for lunches are 43% hamburgers, 37% hot dogs, 12% sausage rolls, and 8% veggie burgers. Today he sells 189 lunches. Of those, 72 are hamburgers, 71 are hot dogs, 27 are sausage rolls, and 19 are veggie burgers. Was today’s food sale pattern significantly different from the past food sale pattern?

a. Create a table of observed and expected frequencies.

b. Calculate χ².

c. At what level of confidence can you reject the null hypothesis?