So I have a question with my teacher's solution below and I'm confused about one of the steps in their solution. I would appreciate some clarification.
Two brands of coffee were compared. Two independent random samples of 50 people each were asked to taste either Brand A or Brand B coffee, and indicate whether they liked it or not. Eighty four percent of the people who tasted Brand A liked it; the analogous sample proportion for Brand B was ninety percent.
(A) At α = 0.01, is there a significant difference in the proportions of individuals who like the two coffees? Use the p-value approach.
So I circled in blue a step where I'm confused about in the teacher's solution. I don't understand why P(Z<-0.89) = 0.2061.
On the z-score table -0.89 is equal to 0.1867 so shouldn't it be that value instead? where did 0.2061 come from? Is it possible that the teacher made an error or am I not understanding something?
2*pnorm(-.89)
returns 0.3734659. $\endgroup$