Question: As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, the un-popped kernels were counted. There were 86.

(a) Construct a 90 percent confidence interval for the proportion of all kernels that would not pop.

(b) Check the normality assumption.

(c) Try the Very Quick Rule .

Does it work well here? Why, or why not?

(d) Why might this sample not be typical?