24.3 A high school principal was concerned that several of her teachers were awarding “A” grades at vastly different rates—she had heard many complaints from students and parents. She compiled the data on the teachers and decided to see if there was in fact a statistically significant difference. Her first look at the grades gave her the idea that there was indeed a difference. Can you write the null and alternative hypotheses, select the appropriate statistical test, conduct the analysis, and then interpret the results? The data are as follows—the teacher’s name and the number of “A” grades are given in parentheses: Thomas

(6), Maryann (10), Marta (12), Berta (8), and Alex (10).