Asurvey of a random sample of moviegoers shows that 40% purchase popcorn to eat while watching the movie. if a theater has 80 people in it, how many people should you expect to have purchased popcorn?

Proportion of moviegoers who buy popcorn = p = 40% = 0.40

Total number of people = n = 80

The expected number of people who will buy popcorn will be equal to the product of the proportion p and the total number of people n.

So,

Expected Number of buyers = np 
= 0.40 x 80
= 32

Thus, from 80 moviegoers we would expected 32 of them to buy popcorn.